Light-emitting device having mixed layer including hole transporting compound

ABSTRACT

A light-emitting device includes a transistor over a substrate and an insulating film over the transistor. The light-emitting device further includes a wiring over the insulating film and a light-emitting element. The insulating film includes a first opening and a second opening, and the wiring is electrically connected to the transistor through the first opening. The light-emitting element is provided in the second opening, and includes a first electrode, a second electrode, and an organic compound layer provided between the first electrode and the second electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/265,212, filed Nov. 5, 2008, now allowed, which is a is acontinuation of U.S. application Ser. No. 10/062,005, filed Jan. 31,2002, now abandoned, which claims the benefit of a foreign priorityapplication filed in Japan as Serial No. 2001-26184 on Feb. 1, 2001, allof which are incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a luminescent device using an organicluminescent element having an anode, a cathode, and a film (referredbelow to as “organic compound layer”), which includes an organiccompound adapted to effect luminescence upon application of an electricfield. Specifically, the present invention relates to a manufacturing ofa luminescent element which requires a lower drive voltage and has alonger life than luminescent devices of the related art. Further, theluminescent device described in the specification of the presentapplication indicates an image display device or a luminescent device,which use an organic luminescent element as luminescent element. Also,the luminescent device includes all of modules, in which a connector,for example, an anisotropic electroconductive film (FPC: Flexibleprinted circuit) or a TAB (Tape Automated Bonding) tape or a TCP (TapeCarrier Package) is mounted to an organic luminescent element, modules,in which a printed-circuit board is provided on a TAB tape or a tip endof a TCP, or modules, in which an IC (integrated circuit) is directlymounted on an organic luminescent element in the COG (Chip On Glass)system.

2. Description of the Related Art

An organic luminescent element is one adapted to effect luminescenceupon application of an electric field. A mechanism for luminescence hasbeen said to reside in that an organic compound layer is interposedbetween electrodes, upon application of voltage thereto electrons filledfrom a cathode and holes filled from an anode recombine together at acenter of luminescence in the organic compound layer to form moleculeexcitons, and the molecule excitons discharge energy to produceluminescence when returned to the base state.

In addition, kinds of molecule excitons formed by the organic compoundcan include a singlet excited state and a triplet excited state, whilethe specification of the present invention contains the case whereeither of the excited states contributes to luminescence.

In such organic luminescent element, an organic compound layer isnormally formed in a thin film below 1 μm. Also, since the organicluminescent element is a self-luminescent type one, in which the organiccompound layer itself emits light, a backlight used in a conventionalliquid crystal display is not necessary. Accordingly, the organicluminescent element can be very advantageously formed to be thin andlightweight.

Also, with, for example, an organic compound layer of about 100 to 200nm in thickness, a time period having elapsed from filling of a carrierto recombination thereof is in the order of several tens of nanosecondtaking account of the extent of movement of the carrier in the organiccompound layer, and luminescence is achieved in the order of less thanone micro second even when the procedure from the recombination of thecarrier to luminescence is included. Accordingly, one of the features isthat the speed of response is very large.

Further, since the organic luminescent element is a carrier-filling typeluminescent element, it can be driven by DC voltage, and is hard togenerate noise. With respect to drive voltage, an adequate luminance of100 cd/m² is achieved at 5.5 V by first making the thickness of anorganic compound layer a uniform, super-thin film of around 100 nm,selecting an electrode material, which reduces a carrier filling,barrier relative to the organic compound layer, and further introducing,a single hetero structure (double structure) (Literature 1: C. W. Tangand S. A. VanSlyke, “Organic electroluminescent diodes”, Applied PhysicsLetters, vol. 51, No. 12, 913-915 (1987)).

Owing to such performances as thin and lightweight, high-speedresponsibility, DC low voltage drive, and the like, organic luminescentelements have been given attention as next-generation flat panel displayelements. Also, since organic luminescent elements are ofself-luminescent type and large in angle of visibility, they arecomparatively favorable in visibility and believed to be effective aselements used for displays in portable equipments.

Hereupon, in the constitution of an organic luminescent elementdescribed in Literature 1, a carrier filling barrier is made small byusing as a cathode a relatively stable Mg:Ag, alloy of low work functionto enhance an electron injecting quality. This makes it possible to filla large amount of carrier into the organic compound layer.

Further, the recombination efficiency of the carrier is improved byleaps and bounds by application of a single hetero structure, in which ahole transporting layer composed of a diamine compound and an electrontransporting luminescent layer composed of tris(8-quinolinolato)aluminium (hereinafter written as “Alq₃”) are laminated as an organiccompound layer, which is explained below.

In the case of, for example, an organic luminescent element having onlya single Alq₃ layer, a major part of electrons filled from a cathodereaches an anode without recombining with holes, making the luminescentefficiency very low, since Alq₃ is of electron transporting quality.That is, in order to have the single-layered organic luminescent elementefficiently emitting light (or driving at low voltage), it is necessaryto use a material (referred below to as “bipolar material”) capable ofcarrying both electrons and holes in well-balanced manner, and Alq₃ doesnot meet such requirement.

However, application of the single hetero structure described inLiterature 1 causes electrons filled from a cathode to be blocked by aninterface between the hole transporting layer and the electrontransporting luminescent layer to be enclosed in the electrontransporting luminescent layer. Accordingly, the carrier is efficientlyrecombined in the electron transporting luminescent layer to provide forefficient luminescence.

When the concept of such carrier blocking function is developed, itbecomes possible to control a carrier recombining region. As an example,there is a report, according to which success is achieved in enclosingholes in a hole transporting layer and making the hole transportinglayer luminescent by inserting a layer (hole blocking layer), which iscapable of blocking holes, between the hole transporting layer and anelectron transporting layer (Literature 2: Yasunori KIJIMA, NobutoshiASAI and Shin-ichiro TAMURA, “A Blue Organic Luminescent Diode”,Japanese Journal of Applied Physics, Vol. 38, 5274-5277 (1999)).

Also, it can be said that the organic luminescent element described inLiterature 1 is based on, so to speak, that thought of functionalseparation, according to which carrying of holes is performed by thehole transporting layer and carrying and luminescence of electrons areperformed by the electron transporting luminescent layer. Such conceptof functional separation has further grown to a concept of doubleheterostructure (three-layered structure), according to which aluminescent layer is inserted between the hole transporting layer andthe electron transporting layer (Literature 3: Chihaya ADACHI, ShizuoTOKITO, Tetsuo TSUTSUI and Shogo SAITO. “Electroluminescence in OrganicFilms with Three-Layered Structure”, Japanese Journal of AppliedPhysics, Vol. 27, No. 2, L269-L271 (1988)).

Such functional separation has an advantage in that the functionalseparation makes it unnecessary for a kind of organic material to have avariety of functions (luminescence, carrier carrying quality, fillingquality of carrier from electrode, and so on) at a time, which providesa wide freedom in molecular design or the like (for example, it isunnecessary to unreasonably search for bipolar materials). That is, ahigh luminous efficiency can be easily attained by combining materialshaving a good luminous quality and a carrier carrying quality,respectively.

Owing to these advantages, the concept of the laminated structure(carrier blocking function or functional separation) itself described inLiterature 1 has been widely utilized till now.

It is also noted that in the fabrication of these luminescent elements,in particular in mass-production processes, a deposition apparatus ofthe in-line type (multi-chamber scheme) is typically employed in orderto prevent contamination of respective materials upon lamination of ahole transport material and a luminescent material, and an electrontransport material or the like by vacuum evaporation. Additionally anupper plan view of such deposition apparatus is shown in FIG. 13.

In the deposition apparatus shown in FIG. 13, it is possible to performa vacuum evaporation of a cathode and a three-layer lamination structure(double-heterostructure) of a hole transport layer and a luminescentlayer, and an electron transport layer on a substrate having an anode(such as ITO or else), and to perform a sealing processing thereof.

Firstly, transfer a substrate with the anode into a carry-in chamber.The substrate is transferred through a first transfer chamber toward anultraviolet ray irradiation chamber, and is then subjected to cleaningtreatment on the surface of such anode, by irradiation of ultravioletrays in a vacuum environment. Note here that in case the anode is madeof oxides such as ITO, the anode is oxidized here in a pretreatmentchamber.

Next, a hole transport layer is formed in a vapor evaporation chamber1301 while forming luminescent layers (in FIG. 13, three colors of red,green and blue) in vacuum evaporation chambers 1302 to 1304, and formingan electron transport layer in a vacuum evaporation chamber 1305, andthen forming a cathode in a vacuum evaporation chamber 1316. Lastly,sealing processing is carried out in a sealing chamber, therebyobtaining a luminescent element from a carry-out chamber.

One feature unique to the deposition apparatus of the inline type isthat vacuum evaporation of respective layers are being performed indifferent vacuum evaporation chambers 1301 to 1305 respectively.Accordingly, each of the vacuum evaporation chambers 1301 to 1305 mayordinarily be provided with a single evaporation source (note howeverthat in the vacuum evaporation chambers 1302 to 1304, two evaporationsources will possibly be required from time to time for formation of aco-vacuum evaporation layer in the case of fabrication of a luminescentlayer by doping pigment thereinto). To be brief, a specific apparatusarrangement is employed, in which materials of respective layers arehardly mixed into each other.

However, being, a junction between substances of different kinds (inparticular, a junction between insulating materials), the laminatedstructure described above will necessarily produce an energy barrier atan interface the substances. Since the presence of an energy barrierinhibits movements of a carrier at the interface, the two followingproblems are caused.

One of the problems is that it results in a barrier leading, to furtherreduction of drive voltage. Actually, it has been reported with respectto existing organic luminescent elements that an element of asingle-layered structure making use of a conjugate polymer is excellentin terms of drive voltage and holds top data (comparison in luminescencefrom the singlet excited state) in power efficiency (unit; “lm/W”)(Literature 4: Tetsuo Tsutsui “bulletin of organicmolecular/bioelectronics” subcommittee of Society of Applied Physics,Vol. 11, No. 1, P. 8 (2000)).

In addition, the conjugate polymer described in Literature 4 is abipolar material, and can attain a level equivalent to that of thelaminated structure with respect to the recombination efficiency of acarrier. Accordingly, it demonstrates that a single layer structurehaving less interfaces is actually low in drive voltage provided that amethod making use of a bipolar material can make an equivalentrecombination efficiency of a carrier without the use of any laminatedstructure.

For example, there is a method, in which a material for mitigating anenergy barrier is inserted at an interface between an electrode and anorganic compound layer to enhance a carrier filling quality to reducedrive voltage (Literature 5: Takeo Wakimoto, Yoshinori Fukuda. KenichiNagavama, Akira Yokoi, Hitoshi Nakada, and Masami Tsuchida, “Organic ELCells Using Alkaline Metal Compounds as Electron Injection Materials”,IEE TRANSACTIONS ON ELECTRON DEVICES. VOL. 44, NO. 8, 1245-1248 (1977)).In Literature 5, the use of Li₂O as an electron injecting layer has beensuccessful in reduction of drive voltage.

However, the carrier transfer between organic materials (e.g., betweenthe hole transport layer and luminescent layer; the interface willhereinafter be called “organic interface”) remains as an unsettled issueand is considered to be an important point in catching up with the lowdrive voltage provided by the single-layered structure.

Further, the other problem caused by an energy barrier is believed to bean influence on the service life of organic luminescent elements. Thatis, movements of a carrier are impeded, and brilliance is lowered due tobuild-up of charges.

While any definite theory has not been established with respect to suchmechanism of deterioration, there is a report that lowering ofbrilliance can be suppressed by inserting a hole injecting, layerbetween an anode and a hole transporting layer and employing not DCdriving but AC driving of rectangular wave (Literature 6: S. A.VanSlyke, C. H. Chen, and C. W. Tang, “Organic electroluminescentdevices with improved stability”, Applied Physics Letters, Vol. 69, No.15, 2160-2162 (1996)). This can be said to present an experimentalevidence that lowering, of brilliance can be suppressed by eliminatingaccumulation of charges due to insertion of a hole injecting layer andAC driving.

It can be said from the above that on one hand the laminated structurehas an advantage in enabling easily enhancing, the recombinationefficiency of a carrier and enlarging a range of material selection interms of functional separation and on the other hand formation of manyorganic interfaces impedes movements of a carrier and has an influenceon lowering of drive voltage and brilliance.

Additionally in the prior art deposition apparatus, lamination of thehole transport material and luminescent layer material, electrontransport material or else is done in separate chambers provided withits own evaporation source in order to prevent contamination ofrespective materials. However, such apparatus is encountered withproblems that organic interfaces are clearly separated and when asubstrate is driven to move between chambers, impurities such as waterand oxygen can be mixed into the organic interface, in the case offorming the above-noted multilayer structure.

SUMMARY OF THE INVENTION

Hence, the present invention provides deposition apparatuses based onconcepts different from the prior used multilayer structures forfabricating an element having functions of a variety of kinds ofmaterials in a similar manner to the function separation of multilayerstructures while at the same time relaxing energy barriers present inorganic compound layers to thereby enhance the mobility of electricalcarriers. Another object of the invention is to provide depositionmethod employing these deposition apparatuses.

Regarding the energy barrier relaxation in multilayer structures, it isremarkably seen in the technique for insertion of a carrier injectionlayer as found in the Document 5. In other words, at the interface of amultilayer structure having a large energy barrier, insertion of amaterial for relaxing such energy barrier makes it possible to designthe energy barrier into the form of a stair step-like shape.

With such an arrangement, it is possible to increase the injectabilityof electrical carriers from an electrode and to reduce a drive voltageto a certain degree. However, a problem faced with this approach is thatan increase in requisite number of layers would result in an increase inorganic interface number. As suggested from Document 4, this isconsidered to be a cause for the fact that single-layer structures aresuperior to multilayer structures in holding of the top-class data as tothe drive voltage and power efficiency.

Adversely, overcoming this point makes it possible to catch up the drivevoltage/power efficiency of single-layer structure while at the sametime maintaining the merits of multilayer structures (enablingcombination of a variety of materials while avoiding the need for anycomplicated molecular design).

Then in the present invention, in the case of forming an organiccompound layer 103 consisting a plurality of function regions between ananode 101 and a cathode 102 in a luminescent element as shown in FIGS.1A and 1B, not the prior art multilayer structure with the presence ofdistinct interfaces (FIG. 1A) but a structure (FIG. 1B) having a mixedregion 106 comprising both a material constituting a first functionregion 104 and a material constituting a second function region 105between the first function region 104 and the second function region 105is formed.

It is considered that applying the structure shown in FIG. 1B causes anyenergy barrier existing between function regions to decrease whencompared to the prior art structure shown in FIG. 1A, resulting in animprovement in carrier injectability. Practically, while an energy banddiagram in the structure of FIG. 1A is as shown in FIG. 1C, in the caseof forming a structure with a mixed region between function regions asshown in FIG. 1B, its energy band diagram becomes as shown in FIG. 1D.To be brief, the energy barrier between function regions is relaxed byformation of such mixed region therebetween. Thus, it becomes possibleto prevent drive voltage drop-down and luminance reduction.

From the foregoing, with deposition apparatus of the present invention,in the manufacture of a luminescent element which at least includes aregion (first function region) which a first organic compound canexpress function and a region (second function region) which a secondorganic compound different from the substance consisting the firstfunction region can express function and also of a luminescent devicehaving the luminescent element, a feature unique thereto is that a mixedregion comprised of the organic compound constituting the first functionregion and organic compound constituting the second function region isfabricated between the first function region and the second functionregion.

It should be noted that the first organic compound and second organiccompound are different in nature from each other while each having itsnature as selected from the group consisting of hole injectability forreceipt of holes from the anode, hole transportability with holemobility greater than electron mobility, electron transportability withelectron mobility greater than hole mobility, electron injectability forreceipt of electrons from the cathode, blocking ability for enablingpreclusion of movement of either holes or electrons, and luminescentability exhibiting luminescence.

Also note that the organic compound with high hole injectability ispreferably made of phthalocyanine-based compound: the organic compoundwith high hole transportability may be aromatic diamine compound; and,the organic compound with high electron transportability may be a metalcomplex that contains therein quinoline skeleton, metal complexcontaining benzoquinoline skeleton or oxadiazole derivative or triazolederivative or phenanthroline derivative. Furthermore, the organiccompound exhibiting luminescence may preferably be a metal complexcontaining therein quinoline skeleton with stabilized light emission,metal complex containing benzooxazole skeleton, or metal complexcontaining benzothiazole skeleton.

Some combinations of the above-stated first function region and thesecond function region are shown in Table 1 presented below.Combinations A to E may be employable solely (e.g. only “A”) oralternatively some of them are introduced together in a compositefashion (e.g. both “A” and “B”).

TABLE 1 Combination 1st Function Region 2nd Function Region A HoleInjectability Hole Transportability B Electron Injectability ElectronTransportability C Hole Transportability Luminescent ability D ElectronTransportability Luminescent ability E Electron TransportabilityBlocking Ability

Additionally in the case of introduction with composite use of thecombinations C and D (that is, when introducing a mixed region at theboth interfaces of a function region with luminescent ability), bypreventing diffusion of molecular excitons formed in the luminescentregion, it is possible to further increase the luminescent efficiency.Thus it will be preferable that the excitation energy of suchluminescent region is lower than the excitation energy of the holeregion and the excitation energy of electron transport region. In thiscase, since luminescent material poor in carrier transportability isalso utilizable as the luminescent region, there is an advantage thatthe range of selecting material expands accordingly. Note here that theterm “excitation energy” used in this specification is to be understoodto mean an energy difference between the highest occupied molecularorbital (HOMO) and the lowest unoccupied molecular orbital (LUMO).

More preferably, it is designed so that the luminescent region iscomprised of both host material and luminescent material (dopant) low inexcitation energy than the host material and designed such that theexcitation energy of such dopant is lower than the excitation energy ofhole transport region and the excitation energy of electron transportlayer. With such an arrangement, it is possible to permit the dopant toproduce light efficiently while at the same time preventing diffusion ofthe dopant's molecular excitons. In addition, if the dopant is made ofcertain material of the carrier trap type then it is also possible toincrease the recombination efficiency of carriers.

Hereupon, in view of the luminescent efficiency, organic luminescentelements capable of converting energy (referred below to as “tripletexcited energy”), which is discharged when returned to a base state froma triplet excited state, into luminance, have been successivelypresented, and notice has been taken of their luminous efficiency(Literature 7: D. F. O'Brien, M. A. Baldo, M. E. Thompson and S. R.Forrest, “Improved energy transfer in electrophosphorescent devices”,Applied Physics Letters, Vol. 74, No. 3, 442-444 (1999)), (Literature 8:Tetsuo TSUTSUI, Moon-Jae YANG, Masayuki YAHIRO, Kenji NAKAMURA, TeruichiWATANABE, Taishi TSUJI, Yoshinori FUKUDA, Takeo WAKIMOTO and SatoshiMIYAGUCHI, “High Quantum Efficiency in Organic Luminescent devices withIridium-Complex as a Triplet Emissive Center”, Japanese Journal ofApplied Physics, Vol. 38, L1502-L1504 (1999)).

A metal complex, of which central metal is platinum, is used inLiterature 7, and a metal complex, of which central metal is iridium, isused in Literature 8. These organic luminescent elements capable ofconverting triplet excited energy into luminance (referred below to as“triplet luminescent diode”) can attain higher intensity luminance andhigher luminous efficiency than in the related art.

However, Literature 8 has presented an example, in which half-life ofluminance is about 170 hours in the case where the initial luminance isset to 500 cd/m², thus causing a problem in service life of an element.Hereupon, application of the invention to triplet light emitting diodescan provide a highly functional luminescent element, which is long inservice life in addition to high intensity luminance and high luminousefficiency based on luminance from a triplet excited state.

Consequently the case of adding a material capable of converting thetriplet excitation energy to light emission into the mixed region as adopant will also be included in the present invention. Additionally inthe formation of such mixed region, it is permissible that the mixedregion has a concentration gradient.

With the deposition apparatus of the present invention, the feature liesin that a plurality of function regions are deposited within the samedeposition chamber having a plurality of evaporation sources to therebyform a luminescent element having the mixed region stated supra.

An explanation will now be given of a deposition chamber 210 as used inthe deposition apparatus of this invention with reference to FIG. 2A. Asshown in FIG. 2A, a metal mask 202 being fixed to a holder 201 isfurnished beneath a substrate 200, with an evaporation source 203 a to203 c being, provided further beneath it. Evaporation sources 203 (203 ato 203 c) comprises organic compounds 204 (204 a to 204 c) forfabrication of organic compound layer, material chambers 205 (205 a to205 c) for preparing the organic compounds therein, and shutters 206(206 a to 206 c). Note here that in the deposition apparatus of thisinvention, it is recommendable that either the evaporation source or asubstrate to be subjected to vacuum evaporation be movably (rotatably)arranged to ensure that film is fabricated uniformly.

Meanwhile, the material chambers 205 (205 a to 205 c) are made ofconductive metal material and have a structure shown in FIG. 17. Notethat the organic compounds 204(204 a to 204 c) are vaporized and thendeposited onto a surface of the substrate 200 upon heat up of theinternal organic compounds 204 (204 a to 204 c) due to resistanceoccurring when a voltage is applied to the material chambers 205 (205 ato 205 c). Also note that the term “surface of the substrate 200” is tobe understood to involve the substrate and more than one thin-film asformed over this substrate, here, an anode is formed on the substrate.

In addition the shutters 206 (206 a to 206 c) control vacuum evaporationof the vaporized organic compounds 204 (204 a to 204 c). In brief, whenthe shutters are opened, it is possible to deposit the vaporized organiccompounds 204 (204 a to 204 c) due to heat application by vacuumevaporation.

Additionally it will be desirable that the organic compounds 204 (204 ato 204 c) be pre-vaporizable by heat application prior to the vacuumevaporation process for enabling effectuation of any vacuum evaporationimmediately after the shutters 206 (206 a to 206 c) are opened duringvacuum evaporation, thus shortening a time period required fordeposition.

In addition, in the deposition apparatus embodying the invention, anorganic compound layer having, a plurality of function regions is formedwithin a single deposition chamber, evaporation sources 203 a to 203 care provided. Organic compounds vaporized at respective evaporationsources 203 a to 203 c behave to upwardly and then pass through openings(not shown) that are defined in the metal mask 202 to be deposited onthe substrate 200.

Initially a first organic compound 204 a furnished in the first materialchamber 205 a is subject to vacuum evaporation. Note here that the firstorganic compound 204 a is vaporized in advance by resistive heat up andthus dispersed in the direction of substrate 200 upon opening of theshutter 206 a during vacuum evaporation. Whereby, it is possible to forma first function region 210 shown in FIG. 2B.

And, while letting the first organic compound 204 a kept deposited, openanother shutter 206 b for execution of vacuum evaporation of a secondorganic compound 204 b furnished in the second material chamber 205 b.Note that the second organic compound also is pre-vaporized by resistiveheat up and thus dispersed in the direction of substrate 200 uponopening of the shutter 206 b during, vacuum evaporation. Here, it ispossible to form a first mixed region 211 which consists essentially ofthe first organic compound 204 a and the second organic compound 204 b.

And, after a while, close only the shutter 206 a for vacuum evaporationof the second organic compound 204 b. Thus it is possible to form asecond function region 212.

It should be noted that although one specific method for forming themixed region through simultaneous vacuum evaporation of two kinds oforganic compounds is shown here, it is also possible to form the mixedregion between the first function region and second function region bydepositing the first organic compound and, thereafter, depositing thesecond organic compound in the vacuum evaporation environment of thefirst organic compound.

Next, while letting the second organic compound 204 b kept deposited,open a shutter 206 c for execution of vacuum evaporation of a thirdorganic compound 204 c as has been furnished in the third materialchamber 205 c. Note that the third organic compound 204 c is alsopre-vaporized by resistive heat up and thus dispersed in the directionof substrate 200 upon opening of the shutter 206 c during vacuumevaporation. Here, it is possible to form a second mixed region 213which consists essentially of the second organic compound 204 b and thethird organic compound 204 c.

And, after a while close only the shutter 206 b for vacuum evaporationof the third organic compound 204 c. Thus it is possible to form a thirdfunction region 214.

Lastly, a cathode is formed, thereby completing a luminescent element asfabricated by the deposition apparatus of the present invention.

Further, regarding other organic compound layers, as shown in FIG. 2C,after forming a first function region 220 using the first organiccompound 204 a, form a first mixed region 221 consisting essentially ofthe first organic compound 204 a and the second organic compound 204 b,and further form a second function region 222 by using the secondorganic compound 204 b. Then, simultaneously perform vacuum evaporationof third organic compound 204 c while letting shutter 206 c opentemporarily during formation of the second function region 222, therebyforming a second mixed region 223.

After a while, close the shutter 206 c to thereby again form the secondfunction region 222. Then form a cathode, thus forming a luminescentelement.

It must be noted that in view of the fact that with the depositionapparatus of this invention the deposition is performed by use of theplurality of material chambers within the same deposition chamber, amaterial chamber with the organic material used for deposition may bedesigned to move at an optimal location beneath the substrate duringdeposition process in order to improve the deposition property or,alternatively, the substrate is modified to have a function of moving atan optimal position overlying the material chamber for the same purpose.

Furthermore, the deposition chamber of this invention is provided withan attachment-preventing shield 207 for preventing attachment of organiccompounds to the inner wall of such deposition chamber during vacuumevaporation. Providing this attachment-preventing shield 207 makes itpossible to deposit those organic compound components that have failedto be deposited on the substrate. Around the attachment-preventingshield 207, a heater 208 is provided in contact therewith, wherein theuse of this heater 208 enables the entirety of suchattachment-preventing shield 207 to be heated. Additionally, heating theattachment-preventing shield 207 makes it possible to vaporize theorganic compounds attached to the shield 207. This in turn makes itpossible to achieve successful cleaning of the interior of depositionchamber.

As the deposition apparatus of the invention capable of fabricating theabove-discussed organic compound layers enables formation of an organiccompound layer having a plurality of function regions within the samedeposition chamber, it is possible to form a mixed region at theinterface between function regions without letting the function regioninterface be contaminated by impurities. From the foregoing, it isapparent that a luminescent element comprising, multiple functions ismanufacturable without showing any distinct multilayer structures (thatis, without associating any distinct organic interfaces).

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A through 1D are diagrams for explanation of an element structureas fabricated by a deposition apparatus of the present invention;

FIG. 2A is a diagram for explanation of a deposition chamber and FIGS.2B and 2C are diagrams of elements as fabricated by a deposition chambershown in FIG. 2A;

FIGS. 3A and 3B are diagrams explaining about a deposition apparatus;

FIGS. 4A through 4E are diagrams for explanation of a metal maskalignment method;

FIG. 5 is a diagram explaining on a deposition apparatus:

FIGS. 6A and 6B are diagrams explaining on a deposition chamber;

FIGS. 7A and 7B are diagrams explaining, on a deposition apparatus;

FIGS. 5A and 8B are diagrams explaining on a deposition apparatus;

FIG. 9 is a diagram explaining on a luminescent device;

FIGS. 10A and 10B are diagrams explaining, on a seal structure;

FIG. 11 is a diagram explaining on a luminescent device;

FIGS. 12A through 12H are diagrams showing, examples of electricalinstruments;

FIG. 13 is a diagram for explanation of one typical prior art:

FIG. 14 is a diagram explaining on a deposition apparatus; and

FIG. 15 is a diagram explaining on a luminescent device.

FIGS. 16A through 16C are diagrams explaining on a pixel portion.

FIG. 17 is a diagram explaining on material chambers.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment Mode

An arrangement of deposition apparatus of the present invention will beexplained with reference to FIGS. 3A and 3B. FIG. 3A is a diagramshowing, an upper plan view of the deposition apparatus, and FIG. 3Bshows a cross-sectional view thereof. Note here that common componentswill be designated by common reference numerals. Also there is shown anexample which is arranged so that three kinds of organic compound layers(red, green, blue) are formed in each deposition chamber of a depositionapparatus of the inline scheme having three deposition chambers.

In FIG. 3A, reference numeral “300” denotes a loading chamber, wherein asubstrate prepared in this load chamber is transferred toward a firstalignment chamber 301. Note that in the first alignment chamber 301,alignment of a metal mask 303 fixed to a holder 302 in advance is donewith the holder 302, thereby a substrate 304 of pre-vacuum evaporationis formed on the alignment-finished metal mask 303, wherein oneelectrode (here, anode) comprising a luminescent element is formed onthe substrate 304. Whereby, the substrate 304 and metal mask 303 aremade integral together to be transferred toward a first depositionchamber 305.

An explanation will now be given of a positional relationship of theholder 302 for fixation of the metal mask 303 and substrate 304 withreference to FIGS. 4A through 4E. Note that in these drawings,components identical to those of FIGS. 3A and 3B will be denoted by thesame reference numerals.

A sectional structure is shown in FIG. 4A. The holder 302 shown hereinis generally constituted from a mask holder 401, a shaft 402, asubstrate holder 403, control mechanism 404 and auxiliary pins 405.Additionally the metal mask 303 is fixed in a way aligned with aprojection 406 on the mask holder 401, with the substrate 304 mounted onthe metal mask 303. Additionally the substrate 304 on the metal mask 303is fixed by the auxiliary pins 405.

An upper plan view in a region 407 of FIG. 4A is shown in FIG. 4B.Additionally the substrate 304 is fixed by the substrate holder 403shown in FIG. 4A and FIG. 4B.

Further, a sectional view as taken along line B-B′ of FIG. 4B is shownin FIG. 4C. Assuming that the position of the metal mask 303 shown inFIG. 4C is at the time of deposition, a position of the metal mask 303shown in FIG. 4D with the shaft 402 moved in Z-axis direction is duringalignment process.

At the process step of FIG. 4D, the shaft 402 is movable in any one ofX-axis and Y-axis, and Z-axis directions, further, movement of gradient(H) of an X-Y plane with respect to the Z-axis is also possible.Additionally, the control mechanism 404 outputs a movement informationfrom both a position information obtained from a charge-coupled device(CCD) camera and a position information input therein in advance,thereby the position of the mask holder can be identical with aspecified position through the shaft 402 coupled to the controlmechanism 404.

In addition, an enlarged view of the metal mask 303 in a region 408 isshown in FIG. 4E. The metal mask 303 as used herein is structured from amask a409 and a mask b410 formed using different materials each other.Additionally during vacuum evaporation, organic compounds that havepassed through these openings 411 will be fabricated on the substrate.Their shapes are contrived to improve the deposition accuracy uponexecution of vacuum evaporation using the masks, and are used in such amanner that the substrate 304 and the mask b410 are in contact with eachother.

When alignment of the metal mask 303 is completed, let the shaft move inthe Z-axis direction causing the metal mask 303 to again move at theposition of FIG. 4C and then let the metal mask 303 and substrate 304 befixed together by the auxiliary pins 405, thus making it possible tocomplete the alignment of the metal mask 303 along with the positioningbetween the metal mask 303 and the substrate 304.

Note that in this embodiment, the openings of the metal mask 303 may beof a rectangular, elliptical, or linear shape, in addition, these may bedesigned into a matrix-like layout or delta layout.

The first deposition chamber 305 in FIG. 3A is provided with a pluralityof evaporation sources 306. Additionally each the evaporation sources306 consists of a material chamber (not shown) in which organiccompounds are prepared and a shutter (not shown) for controlling throughopen/close operations dispersion of vaporized organic compound in thematerial chamber toward outside of the material chamber.

In addition, the plurality of evaporation sources 306 provided in thefirst deposition chamber 305 are provided with organic compounds havingdifferent functions for constituting an organic compound layer of aluminescent element, respectively. Note here that the organic compoundsas used herein may refer to organic compounds having its nature of holeinjectability for receipt of holes from the anode, hole transportabilitywith hole mobility greater than electron mobility, electrontransportability with electron mobility greater than hole mobility,electron injectability for receipt of electrons from the cathode,blocking, ability for enabling inhibition of movement of either holes orelectrons, and luminescent ability exhibiting light emission.

Note here that the organic compound with a high hole injectability maypreferably be phthalocyanine-based compound; the organic compound with ahigh hole transportability is preferably aromatic diamine compound; and,the organic compound with a high electron transportability is preferablya metal complex containing benzoquinoline skeleton, oxadiazolederivative, triazole derivative, or still alternatively phenanthrolinederivative. Further, the organic compound exhibiting luminescent abilityis preferably a metal complex containing quinoline skeleton, metalcomplex containing benzooxazole skeleton, or metal complex containing,benzothiazole skeleton, which emit a steady light.

In the first deposition chamber 305, the organic compounds provided inthese evaporation sources are deposited by a vacuum evaporation inorder, using, the method discussed in FIG. 2A, resulting in formation ofa first organic compound layer (here, red) having a plurality offunction regions and mixed regions.

Next, the substrate 304 is transported toward a second alignment chamber307. In the second alignment chamber 307, after once substrate 304 isseparated from the metal mask 303, alignment of the metal mask 303 isdone in such a manner that it matches a position whereat a secondorganic compound layer is to be fabricated. And, after completion of thealignment, the substrate 304 and the metal mask 303 are overlapped witheach other and fixed together.

And, transfer the substrate 304 toward a second deposition chamber 308.Similarly the second deposition chamber 308 is also provided with aplurality of evaporation sources. In a similar way to the firstdeposition chamber 305, a plurality of organic compounds are depositedby a vacuum evaporation in order, resulting, in formation of a secondorganic compound layer (here, green) having a plurality of functionregions and mixed regions.

Further, transfer the substrate 304 toward a third alignment chamber309. In the third alignment chamber 309, after once the substrate 304 isseparated from the metal mask 303, alignment of the metal mask 303 isdone in such a way that it matches a position whereat a third organiccompound layer is to be fabricated. And, after completion of thealignment, the substrate 304 and metal mask 303 are overlapped with eachother and fixed together.

And, transfer the substrate 304 to a third deposition chamber 310.Similarly the third deposition chamber 310 is also provided with aplurality of evaporation sources. In a similar way to that of the otherdeposition chambers, a plurality of organic compounds are deposited by avacuum evaporation in order, resulting in formation of a third organiccompound layer (here, blue) having a plurality of function regions andmixed regions.

Lastly the substrate 304 is transferred to an unload chamber 311 andthen taken outwardly of the deposition apparatus.

Performing in this way the alignment of the metal mask 303 in thealignment chamber once at a time whenever a different organic compoundlayer is formed, a plurality of organic compound layers can be formedwithin the same apparatus. As function regions consisting of a singleorganic compound layer is deposited in the same deposition chamber inthis way, it is possible to avoid impurity contamination betweenadjacent function regions. Furthermore in this deposition apparatus,since it is possible to form a mixed region between different functionregions, it becomes possible manufacture a luminescent element havingmultiple functions without indicating any distinct multilayerstructures.

Additionally although there is shown in this embodiment a depositionapparatus which operates up to the formation of the organic compoundlayers, the deposition apparatus of the present invention should not belimited only to this structure and may alternatively be modified to havea structure comprising a deposition chamber in which the cathode isformed on an organic compound layer and a processing chamber capable ofsealing the luminescent element. Additionally the deposition order ofthe organic compound layers which emit red, green and blue light shouldnot be limited to the above-stated one.

Moreover, there may also be provided a means for cleaning the alignmentand deposition chambers as indicated in this embodiment mode. Also notethat in case such means is provided in the region 312 of FIG. 3, it ispossible to provide a cleaning preliminary chamber 313 shown in FIG. 14.

In the cleaning preliminary chamber 313, let radicals generate bydecomposition of a reactive gas such as NF₃ or CF₃ and then introducethem into the second alignment chamber 307 to thereby enable cleaning atthe second alignment chamber 307. Note here that the metal mask can becleanup by providing used metal mask in the second alignment chamber 307in advance. Also note that introducing the radicals into the seconddeposition chamber 308 also makes it possible to clean up the inside ofthe second deposition chamber 308. Additionally the second alignmentchamber 307 and second deposition chamber 308 are connected with thecleaning preliminary chamber 313 through gates (not shown) respectively,wherein the gates are designed to open upon introduction of radicals.

Embodiment 1

An explanation will be given of the case where the deposition apparatusof the present invention is the inline scheme, with reference to FIG. 5.In FIG. 5, reference numeral 501 denotes a load chamber, from which asubstrate is transported. Note that the term substrate as used in thisembodiment is to be understood to mean the one with either an anode orcathode (anode used in this embodiment) for use as one electrode of aluminescent element being formed thereon. In addition the load chamber501 comes with a gas exhaust system 500 a, wherein this exhaust system500 a is constituted including a first valve 51, a turbo molecular pump52, a second valve 53, a third valve 54 and a dry pump 55.

Additionally in this embodiment, as the material used for inside ofrespective processing chambers such as a gate-blocked load chamber, analignment chamber, a deposition chamber, a sealing chamber and anunloading chamber, a material such as aluminum or stainless steel (SUS)with mirror surfaces through treatment of electro polishing is used onthe internal wall planes thereof due to its capability to reduce anadsorption of the impurity such as oxygen and water by making surfacearea of the inside wall smaller. In addition, internal members made ofmaterial such as ceramics or else are employed as the inside materialwhich are treated that pores become extremely less. Note that thesematerials have surface smoothness with the center average roughnessbeing less than or equal to 30 Å.

Although the first valve 51 is a main valve having a gate valve, abutterfly valve that functions also as a conductance valve willalternatively be used. The second valve 53 and the third valve 54 arefore valves. First, a pressure of the load chamber 501 is roughlyreduced by the dry pump 55 with the second valve 53 opened, next, apressure of the load chamber 501 is reduced to a high degree of vacuumby the turbo molecular pump 52 with the first valve 51 and third valve54 open. Note that the turbo molecular pump may be replaced with amechanical booster pump; alternatively, the turbo molecular pump isusable after increased the vacuum degree by the mechanical booster pump.

Next, the one indicated by numeral 502 is an alignment chamber. Here,alignment of a metal mask and positioning of a substrate on the metalmask are done for deposition at a deposition chamber to which it willnext be transferred. This will be called alignment chamber A502.Additionally, the method explained in FIGS. 4A through 4E may beemployed in the alignment method here. Additionally the alignmentchamber A502 comprises a gas exhaust system 500 b and is shut andshielded from the load chamber 501 by a gate, not shown.

Further, the alignment chamber A502 is provided with a cleaningpreliminary chamber 513 a for producing therein radicals bydecomposition of a reactive gas such as NF₃ or CF₄ or else and thenintroducing this into the alignment chamber A502, to thereby enable ofcleanup at the alignment chamber A502. Note that the used metal mask canbe cleanup by providing the metal mask in the alignment chamber A502 inadvance.

Next, numeral 503 denotes a deposition chamber for fabrication of afirst organic compound layer by vacuum evaporation methods, which willbe called deposition chamber A503 hereinafter. The deposition chamberA503 comprises an exhaust system 500 c. In addition, this is shut andshielded from the alignment chamber A502 by a gate, not shown.

In a similar way to the alignment chamber A502, the deposition chamberA503 is provided with a cleaning preliminary chamber 513 b. Note herethat the interior of the deposition chamber A503 can be cleanup byintroducing into the deposition chamber A503 radicals produced throughdecomposition of a reactive gas such as NF₃ or CF₄ or else.

In this embodiment, a deposition chamber that has the structure shown inFIG. 2A is provided as the deposition chamber A503 for fabrication ofthe first organic compound layer which emits red light. Additionallyprovided as the evaporation sources are a first evaporation sourceprovided with an organic compound with hole injectability, a secondevaporation source provided with an organic compound with holetransportability, a third evaporation source provided with an organiccompound with hole transportability for use as a host of organiccompound with luminescent ability, a fourth evaporation source providedwith an organic compound with luminescent ability, a fifth evaporationsource provided with an organic compound with blocking ability, and asixth evaporation source provided with an organic compound with electrontransportability.

It is also noted that in this embodiment, copper phthalocyanine(abbreviated as “Cu—Pc” hereinafter) is used as the organic compoundwith hole injectability that provided in the first evaporation source:4,4′-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl (abbreviated as “α-NPD”hereafter) is used as the organic compound with hole transportabilitybeing provided in the second evaporation source;4,4′-dicarbazole-biphenyl (“CBP”) is used as the organic compound whichbecomes the host provided in the third evaporation source;2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin-platinum (“PtOEP”) isused as the organic compound with luminescent ability provided in thefourth evaporation source; bathocuproin (“BCP”) is used as the organiccompound with blocking ability provided in the fifth evaporation source;and, tris(8-quinolinolat) aluminum (“Alq₃”) is used as the organiccompound with electron transportability provided in the sixthevaporation source.

It is noted that the organic compound layer comprising regions havingthe functions of hole injectability, hole transportability, luminescentability, and electron transportability can be formed over the anode bydepositing these organic compound in order through a vacuum evaporation.

Also note that in this embodiment, a mixed region is formed at aninterface between different function regions by simultaneous vacuumevaporation of organic compounds consisting of both function regions. Tobe brief, mixed regions are formed respectively at an interface betweenthe hole injection region and the hole transport region and at aninterface between the hole transport region and the electron transportregion including luminescent region.

Practically, after formed a first function region through deposition ofCu—Pc to a thickness of 15 nm, both Cu—Pc and α-NPD are deposited by avacuum evaporation at a same time to thereby form a first mixed regionwith a film thickness of 5 to 10 nm. Then, fabricate a film of α-NPD toa thickness of 40 nm to thereby form a second function region, followedby formation of a second mixed region with a thickness of 5 to 10 nm bysimultaneous vacuum evaporation of α-NPD and CBP. Thereafter, fabricatea film of CBP to a thickness of 25 to 40 nm, thus forming a thirdfunction region. At the step of forming the third function region, bothCBP and PtOEP are deposited at a same time, thereby forming a thirdmixed region at the entirety or part of the third function region. Notehere that the third mixed region has luminescent ability. Further, bothCBP and BCP are deposited by simultaneous vacuum evaporation to a filmthickness of 5 to 10 nm, thereby forming a fourth mixed region. Inaddition, a BCP film is fabricated to a thickness of 8 nm, thus forming,a fourth function region. Furthermore, BCP and Alq₃ are deposited bysimultaneous vacuum evaporation to a film thickness of 5 to 10 nm,resulting in formation of a fifth mixed region. Lastly a film of Alq₃ isformed to a thickness of 25 nm, thus enabling formation of a fifthfunction region. With the above process steps, a first organic compoundlayer is thus formed.

It should be noted that in the above explanation concerning the firstorganic compound layer six kinds of organic compounds different infunction from one another are provided in six evaporation sourcesrespectively and the organic compound layer is then formed by vacuumevaporation of these organic compounds. The present invention should notbe limited only to the above and may use a plurality of organiccompounds. Additionally the organic compound provided in a singleevaporation source should not always be limited to a single one and mayalternatively be multiple ones. For example, in addition to a singlekind of material provided in an evaporation source as an organiccompound with luminescent ability, another organic compound that serveas a dopant may be provided together. Note that the first organiccompound layer has a plurality of functions and prior known materialsmay be used as these organic compounds composing an organic compoundlayer which emits the red light.

It is to be noted that the evaporation sources may be designed so that amicrocomputer is used to control the deposition speeds thereof.Additionally, with this arrangement, it is preferable to control theratio of mixture upon simultaneous fabrication of a plurality of organiccompound layers.

Next, the one indicated by numeral 506 is an alignment chamber. Here,alignment of a metal mask and positioning of a substrate on the metalmask are done for deposition at a deposition chamber to which it willnext be transferred. This will be called an alignment chamber B506.Additionally, the method explained in FIGS. 4A through 4E may beemployed in the alignment method here. Additionally the alignmentchamber B506 comprises a gas exhaust system 500 d and is shut andshielded from the deposition chamber A503 by a gate not shown. Itfurther comprises a cleaning preliminary chamber 513 c that is shut andshielded from the alignment chamber B506 by a gate not shown, in asimilar way to the alignment chamber A502.

Next, numeral 507 denotes a deposition chamber for fabrication of asecond organic compound layer by vacuum evaporation, which will becalled the deposition chamber B507. This deposition chamber B507 isprovided with an exhaust system 500 e. In addition it is shut andshielded from the alignment chamber B506 by a gate, not shown. Further,it comprises a cleaning preliminary chamber 513 d which is shut andshielded from the deposition chamber B507 by a gate not shown, in asimilar way to the deposition chamber A503.

In this embodiment a deposition chamber with the structure shown in FIG.2A is provided as the deposition chamber B507 for fabrication of asecond organic compound layer which emits green light. Additionallyprovided as the evaporation sources are a first evaporation sourceprovided with an organic compound with hole injectability, a secondevaporation source and a third evaporation source each provided withorganic compounds with hole transportability, a fourth evaporationsource provided with a host material with hole transportability, a fifthevaporation source provided with an organic compound with luminescentability, a sixth evaporation source provided with an organic compoundwith blocking ability, and a seventh evaporation source provided with anorganic compound with electron transportability.

It is noted that in this embodiment, Cu—Pc is employed as the organiccompound with hole injectability provided in the first evaporationsource: MTDATA is employed as the organic compound with holetransportability provided in the second evaporation source; α-NPD isemployed as the organic compound with hole transportability provided inthe third evaporation source; CBP is employed as the host material withhole transportability provided in the fourth evaporation source:tris(2-phenylpyridine) iridium (Ir(ppy)₃) is employed as the organiccompound with luminescent ability provided in the fifth evaporationsource; BCP is employed as the organic compound with blocking abilityprovided in the sixth evaporation source: and Alq₃ is employed as theorganic compound with electron transportability provided in the seventhevaporation source.

It is noted the second organic compound layer can be formed over theanode by successive vacuum evaporation of these organic compounds, whichcomprises regions having functions of hole transportability, luminescentability, blocking ability and electron transportability.

Also note that in this embodiment, a mixed region is formed at aninterface between different function regions by simultaneous vacuumevaporation of organic compounds forming both the function regions. Morespecifically, mixed regions are formed respectively at an interfacebetween the hole transport region and the blocking region and at aninterface between the blocking region and the electron transport region.

Practically, after formed a first function region through deposition ofCu—Pc to a thickness of 10 nm, both Cu—Pc and MTDATA are deposited by avacuum evaporation at a same time to thereby form a first mixed regionwith a film thickness of 5 to 10 nm. Then, fabricate a film of MTDATA toa thickness of 20 nm to thereby form a second function region, followedby formation of a second mixed region with a thickness of 5 to 10 nm bysimultaneous vacuum evaporation of MTDATA and α-NPD. Thereafterfabricate a film of α-NPD to a thickness of 10 nm, thereby forming athird function region. Then, by simultaneous vacuum evaporation of α-NPDand CBP, a third mixed region is formed in thickness from 5 to 10 nm.Subsequently, fabricate a film of CBP to a thickness of 20 to 40 nm tothereby form a fourth function region. At the step of forming the fourthfunction region, (Ir(ppy)₃) is deposited by simultaneous vacuumevaporation at part or entirety of the fourth function region, thusforming a fourth mixed region; then, simultaneously deposited CBP andBCP by vacuum evaporation to form a fifth mixed region with a thicknessof 5 to 10 nm; next, deposit a BCP film of 10-nm thickness to therebyform a fifth function region; next, simultaneously deposit BCP and Alq₃by vacuum evaporation to form a sixth mixed region with a film thicknessof 5 to 10 nm; lastly, form a film of Alq₃ to a thickness of 40 nm, thusforming a sixth function region to thereby form a second organiccompound layer.

Noted that in the above explanation the organic compound layer is formedby vacuum evaporation from seven evaporation sources provided withorganic compounds having different functions respectively as the secondorganic compound layer. The present invention should not be limited onlyto the above and is modifiable as far as a plurality of evaporationsources. Additionally prior known materials may be used as organiccompounds with a plurality of functions for forming an organic compoundlayer which emits green light.

Next, the one indicated by numeral 508 is an alignment chamber. Here,alignment of a metal mask and positioning of a substrate on the metalmask are done for deposition at a deposition chamber to which it willnext be transferred. This will be called an alignment chamber C508.Additionally, the method explained in FIGS. 4A through 4E may beemployed in the alignment method here. Additionally the alignmentchamber C508 comprises a gas exhaust system 500 f and is shut andshielded from the deposition chamber B507 by a gate not shown. Itfurther comprises a cleaning preliminary chamber 513 e that is shut andshielded from the alignment chamber C508 by a gate not shown, in asimilar way to the alignment chamber A502.

Next, numeral 509 denotes a deposition chamber for fabrication of asecond organic compound layer by vacuum evaporation, which will becalled the deposition chamber C509. This deposition chamber C509 isprovided with an exhaust system 500 g. In addition it is shut andshielded from the alignment chamber C508 by a gate not shown. Further,it comprises a cleaning preliminary chamber 513 f which is shut andshielded from the deposition chamber C509 by a gate not shown, in asimilar way to the alignment chamber A503.

In this embodiment a deposition chamber with the structure shown in FIG.2A is provided as the deposition chamber C509 for fabrication of a thirdorganic compound layer which emits blue light. Additionally provided asthe evaporation sources are a first evaporation source provided with anorganic compound with hole injectability, a second evaporation sourceprovided with organic compound with luminescent ability, a thirdevaporation source provided with blocking ability, a fourth evaporationsource provided with an organic compound with electron transportability.It is noted that in this embodiment Cu—Pc is employed as the organiccompound with hole injectability provided in the first evaporationsource; α-NPD is employed as the organic compound with luminescentability provided in the second evaporation source: BCP is employed asthe organic compound with blocking ability provided in the thirdevaporation source; and, Alq₃ is employed as the organic compound withelectron transportability provided in the fourth evaporation source.

It is noted the third organic compound layer can be formed over theanode by successive vacuum evaporation of these organic compounds, whichcomprises regions having functions of hole injectability, luminescentability, blocking ability and electron transportability.

Also note that in this embodiment, a mixed region is formed at aninterface between different function regions by simultaneous vacuumevaporation of organic compounds forming both the function regions. Morespecifically, mixed regions are formed respectively at an interfacebetween the luminescent region and the blocking region and at aninterface between the blocking region and the electron transport region.

Practically, after formed a first function region through deposition ofCu—Pc to a thickness of 20 nm, both Cu—Pc and α-NPD are deposited by avacuum evaporation at a same time to thereby form a first mixed regionwith a film thickness of 5 to 10 nm. Then, fabricate a film of α-NPD toa thickness of 40 nm to thereby form a second function region, followedby formation of a second mixed region with a thickness of 5 to 10 nm bysimultaneous vacuum evaporation of α-NPD and BCP. Thereafter fabricate afilm of BCP to a thickness of 10 nm, thereby forming a third functionregion. Then, by simultaneous vacuum evaporation of BCP and Alq₃, athird mixed region is formed in thickness from 5 to 10 nm; lastly, forma film of Alq₃ to a thickness of 40 nm, to thereby form a third organiccompound layer.

Noted that in the above explanation the organic compound layer is formedby successive vacuum evaporation from fourth evaporation sourcesprovided with four organic compounds having different functionsrespectively as the third organic compound layer. The present inventionshould not be limited only to the above and is modifiable as far as aplurality of evaporation sources. Also, an organic compound provided ina single evaporation source is not limited to have one kind, may be aplurality of ones. For instance, in addition to a single kind ofmaterial provided in an evaporation source as the organic compound withluminescent ability, another organic compound that serve as a dopant maybe provided together. Note that prior known materials may be used asorganic compounds with a plurality of functions for forming an organiccompound layer which emits blue light.

Additionally in this embodiment, one specific case has been explainedwhere the organic compound layer which emits red light is formed in thefirst deposition chamber A503 while forming the organic compound layerwhich emits green light in the second deposition chamber B507 and alsoforming the organic compound layer which emits blue light in the thirddeposition chamber C509. However, the order of formation of these layersshould not be limited only the above order. One of the organic compoundlayers which emit lights of red, green, and blue, respectively may beformed within one of the deposition chamber A503, deposition chamberB507, and deposition chamber C509. Still alternatively, an additionaldeposition chamber may be provided for forming an organic compound layerwhich emits white light therein.

Next, numeral 510 denotes a deposition chamber for formation of aconductive film being either the anode or the cathode of a luminescentelement (a metal film used as the cathode in this embodiment) by vacuumevaporation, which will be called the deposition chamber D510. Thedeposition chamber D510 comprises an exhaust system 500 h, in addition,is shut and shielded from the deposition chamber C509 by a gate notshown. Further, it comprises a cleaning preliminary chamber 5132 whichis sealed and shielded from the deposition chamber D510 by a gate notshown, in a similar manner to that of the deposition chamber A503.

In this embodiment a deposition chamber with the structure shown in FIG.2A is provided as the deposition chamber D510. Accordingly, in regard toa detailed operation of the deposition chamber D510, refer to theexplanation of FIG. 2A.

In this embodiment, in the deposition chamber D510, an Al—Li alloy film(film made of an alloy of aluminum and lithium) is deposited as theconductive film used as the cathode of the luminescent element.Additionally it will also possible to employ co-vacuum evaporation ofaluminum and an element belonging to either the group I or group II ofthe periodic table.

Alternatively a CVD chamber may be provided here for formation of aninsulating film such as a silicon nitride film, silicon oxide film andDLC film or else as a protective film (passivation film) of theluminescent element. Note that in the case of providing such CVDchamber, it will be preferable that a gas purifying machine be providedfor increasing in advance the purity of a material gases used in the CVDchamber.

Next, numeral 511 denotes a sealing chamber, which comprises an exhaustsystem 500 i. In addition, it is shut and shielded from the depositionchamber D510 by a gate not shown. In the seal chamber 511, processing isto be done for finally enclosing a luminescent element in a sealedspace. This processing is the treatment for protecting the luminescentelement formed against oxygen and water, and employs a means formechanically enclosing it by a cover material or alternatively forenclosing it by either thermally hardenable resin or ultraviolet-rayhardenable resin material.

While the cover material used may be glass, ceramics, plastic or metal,the cover material must have optical transmissivity in cases where lightis emitted toward the cover material side. Additionally the covermaterial and a substrate with the above-stated luminescent elementformed thereon are adhered together by use of a seal material such asthermal hardenable resin or ultraviolet-ray hardenable resin or else,thereby forming an air-tight sealed space by letting the resin behardened through thermal processing or ultraviolet ray irradiationprocessing. It is also effective to provide in this sealed space amoisture absorbable material, typical example of which is barium oxide.

It will also be possible to fill the space between the cover materialand the substrate having the luminescent element formed thereon witheither thermal hardenable resin or ultraviolet-ray hardenable resin. Inthis case, it is effective to add a moisture absorption materialtypically such as barium oxide into either the thermal hardenable resinor ultraviolet-ray hardenable resin.

In the deposition apparatus shown in FIG. 5, a mechanism for irradiationof ultraviolet light to the interior of the seal chamber 511 (referredto as the “ultraviolet light irradiation mechanism” hereinafter) isprovided, which is arranged so that ultraviolet light as emitted fromthis ultraviolet light irradiation mechanism is used to harden theultraviolet-ray hardenable resin.

Lastly, numeral 512 is an unload chamber, which comprises an exhaustsystem 500 j. The substrate with luminescent element formed thereon willbe taken out of here.

Further, the deposition apparatus indicated in this embodiment may beprovided with a function of enabling replacement of an organic compoundas shown in FIGS. 6A and 6B. In FIGS. 6A and 6B, a deposition chamber601 comprises a substrate 602. And an organic compound for formation ofan organic compound layer on the substrate is provided in an evaporationsource 603. Note that, here, a evaporation source 603 is provided in amaterial exchange chamber 604 separated from the deposition chamber 601with the substrate furnished therein through a gate 605. Accordingly, inthis embodiment, the material exchange chamber 604 is separated from thedeposition chamber 601 by closure of the gate 605, organic compoundsfurnished in the evaporation source of the material exchange chamber 604can be added or exchange by returning the interior of the materialexchange chamber 604 to an atmospheric pressure via an exhaust system606 and then taking the organic compounds out as shown in FIG. 6A.

And, after finished addition or exchange of the organic compounds, thematerial exchange chamber 604 is returned to its original state again asshown in FIG. 6B, then, interior of the material exchange chamber 604 isset in a vacuum state by the exhaust system 606, and, after it hasbecome the same pressure condition as the interior of depositionchamber, open the gate 605. Thus it is possible of vacuum evaporationfrom the evaporation source 603 to the substrate 602.

Note that the material exchange chamber 604 is provided with a heaterfor heating the material thus exchanged. Preheating the material makesit possible to remove away impurities such as water or the like. It willbe desirable that a temperature applied at this time be equal to or lessthan 200° C.

As described the above, by using the deposition apparatus shown in FIG.5 (or FIGS. 6A and 6B), exposure of the luminescent element to theoutside air is avoided until the luminescent element is completelyenclosed in the sealed space. Thus, it is possible to manufacture aluminescent device with high reliability.

Embodiment 2

A deposition apparatus of the present invention will be explained withreference to FIGS. 7A and 7B. In FIGS. 7A and 7B, reference numeral 701denotes a transfer chamber, wherein this transfer chamber 701 comprisesa transfer mechanism A702 for performing transport of a substrate 703.The transfer chamber 701 is set in a pressure-reduced atmosphere and iscoupled by a gate with each processing chamber. A substrate istransported to each processing chamber by the transfer mechanism A702upon opening of the gate. Additionally while exhaust pump such as a drypump, a mechanical booster pump, a turbo molecular pump (magneticfloatation type) or cryopump is employable for pressure reduction of thetransfer chamber 701 the turbo molecular pump of the magnetic flotationtype is preferable in order to obtain high-degree vacuum states withhigher purity.

An explanation will be given of each processing chamber below. Note thatthe transfer chamber 701 is set in a pressure-reduced atmosphere so thatall the processing chambers directly coupled to the transfer chamber 701are provided with vacuum pumps (not shown). While dry pumps, mechanicalbooster pumps, turbo molecular pumps (magnetic floatation type) orcryopumps are employable as the vacuum pumps, the turbo molecular pumpsof the magnetic flotation type are preferable in this case also.

First, numeral 704 denotes a load chamber for performing setting(installation) of a substrate. The load chamber 704 is coupled by a gate700 a with the transfer chamber 701, at here a carrier (not shown) witha substrate 703 mounted thereon is arranged. Additionally the loadchamber 704 can also do double-duty as a chamber that transfers asubstrate which element formation is finished toward the sealing,chamber. Additionally the load chamber 704 may alternatively haveseparated rooms for carry-in of the substrate and for carry-out of thesubstrate. Note that the load chamber 704 comprises the above describedvacuum pomp and a purge line for introduction of a high-purity nitridegas or noble gas. Additionally the vacuum pump used herein is preferablya turbo molecular pump. Further, this purge line is provided with a gasrefining machine for removal in advance of impurities (oxygen and water)of such gases to be introduced into the apparatus.

It is also noted that in this embodiment, a substrate which atransparent conductive film used as the anode of luminescent element isformed thereon is used as the substrate 703. In this embodiment thesubstrate 703 is set in a carrier with its deposition surface being,directed downwardly. This is for performing of face-down scheme (alsoknown as “depo-up” scheme) when later performing deposition by vacuumevaporation methods. The face-down scheme is to be understood to mean ascheme for performing deposition while letting the deposition surface ofa substrate being directed downwardly. With this scheme, it is possibleto suppress attachment of contaminant particles such as dusts.

Next, the one indicated by numeral 705 is an alignment chamber foralignment of a metal mask and for matching position between a metal maskand a substrate with either the anode or the cathode of luminescentelement (anode in this embodiment) formed thereon, wherein the alignmentchamber 705 is coupled by a gate 700 b with the transfer chamber 701.Note that a process in combination of the metal mask alignment andpositioning of the substrate and metal mask is done within the alignmentchamber, once at a time whenever a different organic compound layer isformed. In addition, the alignment chamber 705 comprises acharge-coupled device (CCD) known as an image sensor, thereby making itpossible to accurately perform position alignment of the substrate andits associated metal mask in deposition using the metal mask. Note thatwith respect to metal mask alignment, the method discussed in FIGS. 4Athrough 4E may be used.

Further, a cleaning preliminary chamber 722 a is coupled to thealignment chamber 705. An arrangement of the cleaning preliminarychamber 722 a is as shown in FIG. 7B. First the cleaning preliminarychamber 722 a has a μ-wave oscillator 731 for generation of μ waves,wherein μ waves generated at here will be sent through a wave guide tube732 toward a plasma discharge tube 733. Note that μ waves of about 2.45GHz are radiated from the μ wave oscillator 731 used here. In addition,a reactive gases are supplied to the plasma discharge tube 733 from agas inlet tube 734. Additionally here, NF; is used as the reactive gas,although other gases such as CF₄ and ClF₃ may be used as reactive gases.

And, the reactive gas is decomposed by μ wave in the plasma dischargetube 733, causing radicals to generate. These radicals are guided topass through the gas inlet tube 734 to introduce the alignment chamber705 as coupled via a gate (not shown) thereto. Additionally the plasmadischarge tube 733 may be provided with a reflection plate 735 forefficient supplement of μ waves.

And, the alignment chamber 705 comprises a metal mask with an organiccompound layer attached thereto. And open a gate (not shown) providedbetween the cleaning preliminary chamber 722 a and the alignment chamber705, thereby enabling introduction of radicals into the alignmentchamber 705. This makes it possible to perform cleaning of the metalmask.

As the use of μ-wave plasma makes it possible to perform radicalizationof a reactive gas with high efficiency, the rate of creation ofimpurities such as side products or the like is low. In addition, sinceit is different in mechanism from standard radical production, theresultant radicals will no longer be accelerated and radical is notproduced within the interior of the deposition chamber. This makes itpossible to prevent damages within the deposition chamber due to thepresence of a plasma and also damages of the metal mask.

It should be noted that the technique for cleaning the alignment chamberby use of the thus method is one of the preferred modes of the presentinvention so that this invention should not be limited thereto.Accordingly, it may also be performed a dry cleaning by introducingreactive gases into the deposition chamber to thereby produce a plasmawithin this deposition chamber, alternatively, a physical cleaning bysputter methods through introduction of an Ar gas or else.

Next, numeral 706 denotes a deposition chamber used for deposition of anorganic compound layer by vacuum evaporation method, which will becalled the deposition chamber A706 hereinafter. The deposition chamberA706 is coupled via a gate 700 c to the transfer chamber 701. In thisembodiment a deposition chamber with the structure shown in FIG. 2A isprovided as the deposition chamber A706.

With this embodiment, a first organic compound layer capable of emittingred light is formed at a deposition unit 707 within the depositionchamber A706. A plurality of evaporation sources are provided with thedeposition chamber A706, practically, there are provided a firstevaporation source comprising an organic compound material with holeinjectability, a second evaporation source comprising an organiccompound with hole transportability, a third evaporation sourcecomprising an organic compound with luminescent ability, and a fourthevaporation source comprising an organic compound with electrontransportability.

Note that by successive vacuum evaporation of these organic compoundssequential vacuum evaporation, the organic compound layer can be formedabove the anode, which comprises regions having functions of holeinjectability, hole transportability, luminescent ability and electrontransportability.

Additionally in this embodiment, a mixed region is formed at aninterface between different function regions by simultaneous vacuumevaporation of organic compounds forming such both function regions.More specifically, several mixed regions are formed at an interfacebetween the hole injection region and the hole transport region, at aninterface between the hole transport region and the luminescent region,and at an interface between the luminescent region and electrontransport region, respectively.

Noted that in the above explanation the organic compound layer is formedby successive vacuum evaporation from four evaporation sources providedwith four organic compounds having different functions respectively asthe first organic compound layer. The present invention should not belimited only to the above and is modifiable as far as a plurality ofevaporation sources. Also, an organic compound provided in a singleevaporation source is not limited to have one kind, may be a pluralityof ones. For instance, in addition to a single kind of material providedin an evaporation source as the organic compound with luminescentability, another organic compound that serve as a dopant may be providedtogether. Additionally, as the organic compounds having the plurality offunctions and forming the organic compound layer which emits red light,the ones as indicated in Embodiment 1 is employable, although knownmaterials are freely used in combination where necessary.

It is also noted that the deposition chamber A706 is coupled via a gate700 g to a material exchange chamber 714. Also note that the materialexchange chamber 714 is provided with a heater for heating organiccompounds exchanged. Preheating such organic compounds makes it possibleto remove impurities such as water or the like. It will be desirablethat a temperature being applied here be 200° C. or below. In addition,since the material exchange chamber 714 is provided with a vacuum pumpcapable of setting its interior in a pressure reduction, let theinterior be set in such vacuum pressure state after heat up processingby addition or exchange of an organic compound from the outside. And,when it becomes the same pressure state as that within the depositionchamber, open the gate 700 g to thereby enable the evaporation sourcewithin the deposition chamber to be provided with an organic compound.Additionally the organic compound is provided at the evaporation sourcewithin the deposition chamber by means of a transfer mechanism.

Additionally, regarding the deposition process within the depositionchamber A706, refer to the explanation of FIG. 2A.

Note that in a similar way to the alignment chamber 705, a cleaningpreliminary chamber 722 b is coupled to the deposition chamber A700 viaa gate (not shown). Additionally its practical arrangement is similar tothat of the cleaning preliminary chamber 722 a, thus, it is possible byintroducing radicals generated in the cleaning preliminary chamber 722 binto the deposition chamber A706 to remove organic compounds and thelike being internally attached to the deposition chamber A706.

Next, numeral 708 denotes a deposition chamber used for deposition of asecond organic compound layer by vacuum evaporation method, which willbe called the deposition chamber B708 hereinafter. The depositionchamber B708 is coupled via a gate 700 d to the transfer chamber 701. Inthis embodiment a deposition chamber with the structure shown in FIG. 2Ais provided as the deposition chamber B708. With this embodiment, thesecond organic compound layer capable of emitting green light is formedat a deposition unit 709 within the deposition chamber B708.

A plurality of evaporation sources are provided with the depositionchamber B708, practically, there are provided a first evaporation sourcecomprising an organic compound with hole transportability, a secondevaporation source comprising an organic compound with luminescentability, a third evaporation source comprising an organic compound withblocking ability, and a fourth evaporation source comprising an organiccompound with electron transportability.

Note that sequential vacuum evaporation of these organic compounds makesit possible to form on the anode an organic compound layer consistingessentially of regions having functions of hole transportability,luminescent ability, blocking ability and electron transportability.

Additionally in this embodiment, a mixed region is formed at aninterface between different function regions by simultaneous vacuumevaporation of organic compounds forming such both function regions.More specifically, several mixed regions are formed at an interfacebetween the hole transport region and the luminescent region, at aninterface between the luminescent region and the blocking region, and atan interface between the blocking region and electron transport region,respectively.

Noted that in the above explanation the organic compound layer is formedby successive vacuum evaporation from four evaporation sources providedwith four organic compounds having different functions respectively asthe second organic compound layer. The present invention should not belimited only to the above and is modifiable as far as a plurality ofevaporation sources. Also, an organic compound provided in a singleevaporation source is not limited to have one kind, may be a pluralityof ones. For instance, in addition to a single kind of material providedin an evaporation source as the organic compound with luminescentability, another organic compound that serve as a dopant may be providedtogether. Additionally, as the organic compounds having the plurality offunctions and forming the organic compound layer which emits greenlight, the ones as indicated in Embodiment 1 is employable, althoughknown materials are freely used in combination where necessary.

It is also noted that the deposition chamber B708 is coupled via a gate700 h to a material exchange chamber 715. Also note that the materialexchange chamber 715 is provided with a heater for heating organiccompounds exchanged. Preheating such organic compounds makes it possibleto remove impurities such as water or the like. It will be desirablethat a temperature being applied here be 200° C. or below. In addition,since the material exchange chamber 715 is provided with a vacuum pumpso that after introducing organic compounds from the outside it ispossible to set its interior in a pressure reduction by the vacuum pump.And, when it becomes the same pressure state as that within thedeposition chamber, open the gate 700 h to thereby enable theevaporation source within the deposition chamber to be provided with anorganic compound. Additionally the organic compound is provided at theevaporation source within the deposition chamber by means of a transfermechanism.

Additionally, regarding, the deposition process within the depositionchamber B708, refer to the explanation of FIG. 2A.

Note that in a similar way to the alignment chamber 705, a cleaningpreliminary chamber 722 c is coupled to the deposition chamber B708 viaa gate (not shown). Additionally its practical arrangement is similar tothat of the cleaning preliminary chamber 722 a, thus, it is possible byintroducing radicals generated in the cleaning preliminary chamber 722 cinto the deposition chamber B708 to remove organic compounds and thelike being internally attached to the deposition chamber B708.

Next, numeral 710 denotes a deposition chamber used for deposition of athird organic compound layer by vacuum evaporation method, which will becalled the deposition chamber C710 hereinafter. The deposition chamberC710 is coupled via a gate 700 e to the transfer chamber 701. In thisembodiment a deposition chamber with the structure shown in FIG. 2A isprovided as the deposition chamber C710. With this embodiment, the thirdorganic compound layer capable of emitting blue light is formed at adeposition unit 711 within the deposition chamber C710.

A plurality of evaporation sources are provided with the depositionchamber C710, practically, there are provided a first evaporation sourcecomprising an organic compound with hole injectability, a secondevaporation source comprising an organic compound with luminescentability, a third evaporation source comprising an organic compound withblocking ability, and a fourth evaporation source comprising an organiccompound with electron transportability.

Note that sequential vacuum evaporation of these organic compounds makesit possible to form on the anode an organic compound layer consistingessentially of regions having functions of hole injectability,luminescent ability, blocking ability and electron transportability.

Additionally in this embodiment, a mixed region is formed at aninterface between different function regions by simultaneous vacuumevaporation of organic compounds forming such both function regions.More specifically, several mixed regions are formed at an interfacebetween the hole injection region and the luminescent region, at aninterface between the luminescent region and the blocking region, and atan interface between the blocking region and electron transport region,respectively.

Noted that in the above explanation the organic compound layer is formedby successive vacuum evaporation from four evaporation sources providedwith four organic compounds having different functions respectively asthe third organic compound layer. The present invention should not belimited only to the above and is modifiable as far as a plurality ofevaporation sources. Also, an organic compound provided in a singleevaporation source is not limited to have one kind, may be a pluralityof ones. For instance, in addition to a single kind of material providedin an evaporation source as the organic compound with luminescentability, another organic compound that serve as a dopant may be providedtogether. Additionally, as the organic compounds having the plurality offunctions and forming the organic compound layer which emits blue light,the ones as indicated in Embodiment 1 is employable, although knownmaterials are freely used in combination where necessary.

It is also noted that the deposition chamber C710 is coupled via a gate700 i to a material exchange chamber 716. Also note that the materialexchange chamber 715 is provided with a heater for heating organiccompounds exchanged. Preheating such organic compounds makes it possibleto remove impurities such as water or the like. It will be desirablethat a temperature being applied here be 200° C. or below. In addition,since the material exchange chamber 716 is provided with a vacuum pumpso that after introducing organic compounds from the outside it ispossible to set its interior in a pressure reduction by the vacuum pump.And, when it becomes the same pressure state as that within thedeposition chamber, open the gate 700 i to thereby enable theevaporation sources within the deposition chamber to be provided withorganic compounds. Additionally the organic compound is provided at theevaporation source within the deposition chamber by means of a transfermechanism. Additionally, regarding the deposition process within thedeposition chamber C710, refer to the explanation of FIG. 2A.

Note that in a similar way to the alignment chamber 705, a cleaningpreliminary chamber 722 d is coupled to the deposition chamber C710 viaa gate (not shown). Additionally its practical arrangement is similar tothat of the cleaning preliminary chamber 722 a, thus, it is possible byintroducing radicals generated in the cleaning preliminary chamber 722 dinto the deposition chamber C710 to remove organic compounds and thelike being internally attached to the deposition chamber C710.

Next, numeral 712 indicates a deposition chamber for fabricating byvacuum evaporation method a conductive film used as either the anode orcathode of a luminescent element (in this embodiment, a metal film usedas the cathode), which chamber will be called the deposition chamberD712. This deposition chamber D712 is coupled via a gate 700 f to thetransfer chamber 701. In this embodiment, at the deposition unit 713within the deposition chamber D712, an Al—Li alloy film (alloy film ofaluminum and lithium) is to be formed as the conductive film used as thecathode of the luminescent element. It will also be possible to performco-vacuum evaporation of both aluminum and an element belonging toeither the group I or group II of the periodic table at a time. The termco-vacuum evaporation refers to a vacuum evaporation method thatevaporation sources are heated simultaneously and different materialsare mixed together at the deposition step.

It is also noted that the deposition chamber D712 is coupled via a gate700 j to a material exchange chamber 717. Also note that the materialexchange chamber 717 is provided with a heater for heating organiccompounds exchanged. Preheating such organic compounds makes it possibleto remove impurities such as water or the like. It will be desirablethat a temperature being applied here be 200° C. or below. In addition,since the material exchange chamber 717 is provided with a vacuum pumpso that after introducing conductive materials from the outside it ispossible to set its interior in a pressure reduction by the vacuum pump.And, when it becomes the same pressure state as that within thedeposition chamber, open the gate 700 j to thereby enable theevaporation sources within the deposition chamber to be provided withconductive materials.

Note that in a similar way to the alignment chamber 705, a cleaningpreliminary chamber 722 e is coupled to the deposition chamber D712 viaa gate (not shown). Additionally its practical arrangement is similar tothat of the cleaning preliminary chamber 722 a, thus, it is possible byintroducing radicals generated in the cleaning preliminary chamber 722 einto the deposition chamber D712 to remove conductive materials and thelike being internally attached to the deposition chamber D712.

In addition a respective one of the deposition chamber A706, thedeposition chamber B708, the deposition chamber C710 and depositionchamber D712 comprises a mechanism for heating the interior of eachdeposition chamber. Whereby it is possible to remove part of impuritiesin the deposition chambers.

Further note that although dry pumps, mechanical booster pumps, turbomolecular pumps (magnetic floatation type) or cryopumps are employableas the vacuum pumps provided in these deposition chambers, it isdesirable that the cryopumps and dry pumps be used in this embodiment.

In addition, the deposition chamber A706, the deposition chamber B708,the deposition chamber C710 and deposition chamber D712 are reduced inpressure by the vacuum pumps. It is desirable that the finally reacheddegree of vacuum at this time be greater than or equal to 10⁻⁶ Pa. Forexample, with the use of a cryopump with its evacuation rate of 10.000l/s (H₂O), a leakage amount within a deposition chamber must be lessthan or equal to 4.1×10⁻⁷ Pa*m*s⁻¹ for 20 hours, when the interior ofthe deposition chamber is formed of aluminum while letting a surfacearea of the deposition chamber interior measure 10 m². In order toobtain such vacuum degree, it is effective to minimize byelectro-polishing techniques the surface area of the deposition chamberinterior.

Next, numeral 718 denotes a sealing chamber (also known as an enclosingchamber or “glove box”), which is coupled via a gate 700 k to the loadchamber 704. In the sealing chamber 718, processing for finallyenclosing, a luminescent element into a sealed space is performed. Thisprocessing is for protection of the formed luminescent element againstoxygen and water, which employs a means for mechanically enclosing bycover material or alternatively enclosing by using, either thermallyhardenable resin or ultraviolet ray hardenable resin material.

While the cover material used may be glass, ceramics, plastic or metal,the cover material must have optical transmissivity in cases where lightis emitted toward the cover material side. Additionally the covermaterial and a substrate with the above-stated luminescent elementformed thereon are adhered together by use of a seal material such asthermal hardenable resin or ultraviolet-ray hardenable resin or else,thereby forming an air-tight sealed space by letting the resin behardened through thermal processing or ultraviolet ray irradiationprocessing. It is also effective to provide in this sealed space amoisture absorbable material, typical example of which is barium oxide.

It will also be possible to fill the space between the cover materialand the substrate having the luminescent element formed thereon witheither thermal hardenable resin or ultraviolet-ray hardenable resin. Inthis case, it is effective to add a moisture absorption materialtypically such as barium oxide into either the thermal hardenable resinor ultraviolet-ray hardenable resin.

In the deposition apparatus shown in FIG. 7A, a mechanism 719 forirradiation of ultraviolet light to the interior of the sealing chamber718 (referred to as the “ultraviolet light irradiation mechanism”hereinafter) is provided, which is arranged so that ultraviolet light asemitted from this ultraviolet light irradiation mechanism 719 is used toharden the ultraviolet-ray hardenable resin. Attachment of a vacuum pumpmakes also possible to reduce pressure within the sealing chamber 718.In case the above sealing process is done mechanically by robotoperation, it is possible by performing this process to prevent mixtureof oxygen and water because of atmosphere in reduced pressure.Practically it is desired that the concentrations of such oxygen andwater be made less than or equal to 0.3 ppm. Additionally it is alsopossible that the interior of the seal chamber 718 is pressurizedadversely. In this case, the sealing chamber 718 is purged by a nitridegas or noble gas of high purity and pressurized, thereby the invasion ofoxygen or the like from the outside is prevented.

Next, a delivery chamber (pass box) 720 is coupled to the sealingchamber 718. The delivery chamber 720 is provided with a transfermechanism B721 for transferring toward the delivery chamber 720 asubstrate which sealing of the luminescent element is completed in thesealing chamber 718. The delivery chamber 720 also can be set in areduced pressure state by attachment of a vacuum pump thereto. Thisdelivery chamber 720 is the facility that prevents the sealing, chamber718 from being exposed directly to the outside air, from which thesubstrate is removed. Optionally it is also possible to provide a membersupply chamber (not shown) for supplying members to be used in thesealing chamber.

It must be noted that although not shown in diagrams of this embodiment,insulating films with lamination of chemical compounds including siliconsuch as silicon nitride or silicon oxide and with lamination of adiamond like carbon (DLC) film containing carbon on these chemicalcompounds may be formed on a luminescent element after forming theluminescent element. Additionally the term diamond-like carbon (DLC)film refers to an amorphous film with a mixture of diamond bonding (sp³bond) and graphite bond (SP² bond). Note that in this case, a depositionchamber may be provided which comprises a chemical vapor deposition(CVD) apparatus for generating a plasma by application of a self bias tothereby form a thin film through plasma discharge decomposition ofmaterial gases.

Note that in the deposition chamber comprising such chemical vapordeposition (CVD) apparatus, there may be used oxygen (O₂), hydrogen (H₂)methane (CH₄), ammonia (NH₃) and silane (SiH₄). Also note that as theCVD apparatus, there is employable the one that has electrodes of theparallel flat-plate type with RF power supply of 13.56 MHz.

Further, it is also possible to provide a deposition chamber forperforming deposition by sputtering methods (also called sputtermethods). This is due to the fact that deposition by sputtering iseffective in the case of forming the anode after forming organiccompound layers on the cathode of a luminescent element. In other words,it is effective in cases where a pixel electrode is the cathode.Additionally the interior of such deposition chamber is set at anatmosphere with oxygen added to argon during deposition whereby theconcentration of oxygen in a film thus fabricated is well controlled toenable formation of a low resistance film that is high in opticaltransmissivity. Also note that it will be desirable that the depositionchamber be shielded by a gate from the transfer chamber in a similarmanner to the remaining deposition chambers.

It is to be noted that in the deposition chamber for sputtering, amechanism may be provided which is operable to control the temperatureof such substrate deposited. Additionally it is desirable that thesubstrate deposited be kept at temperature ranging from 20 to 150° C.Further, although a dry pump, mechanical booster pump, turbo molecularpump (magnetic floatation type) or cryopump is useable as a vacuum pumpto be provided in the deposition chamber, the turbo molecular pump (themagnetic flotation type) and dry pump are preferably employed in thisembodiment.

As apparent from the foregoing, the use of the deposition apparatusshown in FIGS. 7A and 7B makes it possible to prevent exposure of aluminescent element to the outside air until the luminescent element iscompletely enclosed in an air-tight sealed space, which in turn enablessuccessful manufacture of a luminescent device with high reliability.

Embodiment 3

In this embodiment, a deposition apparatus will be explained withreference to FIGS. 8A and 8B, which is different in substrate transfermethod and structure from the deposition apparatus of the inline type ashas been indicated in the embodiment 1.

In FIGS. 8A and 8B, a substrate 804 as loaded into a load chamber 800 istransported toward a first alignment unit 801 which is coupled theretovia a gate (not shown). Note that the substrate 804 is subjected toalignment by the method discussed in FIGS. 4A through 4E and then fixedto a holder 802 along with a metal mask 803.

And, the substrate 804 is transferred to a first deposition unit 805together with the holder 802. Note here that the first alignment unit801 and the first deposition unit 805 are coupled together via no gatesand have the same space. Then, in this embodiment, a rail 812 isprovided as a means for enabling free movement between the firstalignment unit 801 and the first deposition unit 805, wherein eachprocessing is to be done while the holder 802 is moving along this rail.Additionally the processing position during alignment and deposition iscontrolled by a control mechanism owned by the holder 802.

And in the first deposition unit 805, different organic compounds isdeposited by vacuum evaporation from a plurality of evaporation sources806 furnished with the organic compounds respectively to thereby form afirst organic compound layer. Note that this movement means will also beused in the case of transfer toward a second alignment unit 807 and asecond deposition unit 808 for fabrication of a second organic compoundlayer in a similar way to that discussed above.

Further, in the case of forming a third organic compound also, it issimilarly transferred to a third alignment unit 809 and a thirddeposition unit 810.

As discussed above in this embodiment, it is possible to form threedifferent kinds of organic compound layers within the same space. Thethird deposition unit 810 is coupled via a gate (not shown) to an unloadchamber 811, thus enabling unloading of a substrate with depositioncompleted.

It is noted that the processing method at the alignment units and thedeposition units in this embodiment is similar to that in the alignmentand the deposition chambers of the embodiment 1.

It is also noted that in this embodiment, provision of a partition wallbetween the alignment units and the deposition units makes it possibleto prevent organic compounds from dispersing out of the evaporationsources during deposition toward locations other than the depositionunits.

In the deposition apparatus of this embodiment also, a cleaningpreliminary chamber 813 may be provided for cleaning of the interior ofeach deposition chamber and metal masks.

Forming a plurality of organic compound layers are formed within thesame space by using the deposition apparatus stated above, movementbetween different organic compound layers during formation, thus makingit possible to shorten a time as taken to complete the processing.

Note here that while in the deposition apparatus indicated in thisembodiment it is possible to form three kinds of organic compound layershaving a plurality functions on a substrate with the anode or cathode ofa luminescent through continuous vacuum evaporation processes in thedeposition chamber. It is modifiable that a further deposition chamberfor fabrication of a conductive film is provided for enabling continuousformation of the cathode or anode of such luminescent element.Additionally in the case of forming the cathode, the conductive film maybe an Al—Li alloy film (alloy film of aluminum and lithium) oralternatively a film obtained by co-vacuum evaporation of both aluminumand an element belonging to either the group I or group II of theperiodic table at a time, in the case of forming the anode, there may beused indium oxide, tin oxide, zinc oxide, or an alloys of them (such asITO).

In addition to the above, it is also possible to provide a processingchamber for performing a sealing of the luminescent element thusmanufactured.

Embodiment 4

In this embodiment an explanation will be given of a luminescent devicemanufactured by use of the deposition apparatus of the presentinvention. FIG. 9 is a diagram showing a cross-sectional view of anactive matrix type luminescent device. Note that although thin filmtransistors (referred to as “TFTs” hereinafter) are employed as activeelements, these are replaceable by MOS transistors.

Additionally, although top gate type TFTs (practically planar type TFTs)will be exemplarily indicated as the TFTs, bottom gate type TFTs(typically, inverse stagger type TFTs) is alternatively employable.

In FIG. 9, numeral 901 denotes a substrate, here, which permitstransmission of visible light rays. Practically, a glass substrate, aquartz substrate, a crystallized glass substrate or plastic substrate(including a plastic film) are useable. Note that the substrate 901includes an insulating film provided on the surface thereof.

A pixel portion 911 and a drive circuit 912 are provided on thesubstrate 901. The pixel portion 911 will first be explained below.

The pixel portion 911 is a region that performs image displaying. Aplurality of pixels are present on the substrate, each of which isprovided with a TFT 902 for control of a current flowing in aluminescent element (referred to hereinafter as current controllingTFT), a pixel electrode (anode) 903, an organic compound layer 904 and acathode 905. In addition, numeral 913 denotes a TFT for controlling avoltage applied to the gate of the current controlling TFT (referred toas switching TFT hereinafter).

Preferably here, the current controlling TFT 902 is a p-channel typeTFT. Although it may alternatively be an n-channel TFT, the use ofp-channel TFT makes it possible to suppress consumption of electricalpower in case the current controlling TFT is connected to the anode ofthe luminescent element as shown in FIG. 9. Note however that theswitching TFT 913 may be either n-channel TFT or p-channel TFT.

It is noted that drain of the current controlling TFT 902 iselectrically connected with the pixel electrode 903. In this embodiment,since the pixel electrode 903 is used a conductive material with itswork function within a range of 4.5 to 5.5 eV, the pixel electrode 903functions as the anode of the luminescent element. The pixel electrode903 may typically be made of indium oxide, tin oxide, zinc oxide, orcompounds thereof (such as ITO). The organic compound layer 904 isprovided on the pixel electrode 903.

Further, the cathode 905 is provided on the organic compound layer 904.It is desirable that the cathode 905 be made of a conductive materialwith its work function ranging from 2.5 to 3.5 eV. The cathode 905 istypically made from a conductive film containing alkaline metal elementsor alkali rare metal elements, a conductive film containing aluminum,and one that aluminum or silver is laminated on the above conductivefilms.

In addition the luminescent element 914 comprising the pixel electrode903, the organic compound layer 904, and cathode 905 is covered with aprotective film 906. This protective film 906 is provided for protectionof the luminescent element 914 against oxygen and water. The protectivefilm 906 is made of material such as silicon nitride, siliconoxynitride, aluminum oxide, tantalum oxide or carbon (typically, diamondlike carbon).

An explanation will next be given of the drive circuit 912. The drivecircuit 912 is the region that controls the timing of signals (gatesignal and data signal) being sent to the pixel portion 911, which isprovided with a shift register, a buffer, a latch, an analog switch(transfer gate), or a level shifter. In FIG. 9 a CMOS circuit is shownwhich is made up of an n-channel TFT 907 and p-channel TFT 908 for useas a basic unit of these circuits.

The circuit structure of the shift register, the buffer, the latch, theanalog switch (transfer gate) or the level shifter may be designed in aknown way. Additionally although in FIG. 9 the pixel portion 911 and thedrive circuit 912 are provided on the same substrate, it is alsopossible to electrically connect IC and LSI without providing the drivecircuit 912.

Additionally, although in FIG. 9 the pixel electrode (anode) 903 iselectrically connected to the current controlling TFT 902, this may bemodified into a structure with the cathode connected to the currentcontrolling TFT. In such case, the pixel electrode 903 may be made ofthe same material as that of the cathode 905 while letting the cathodebe made of similar material to that of the pixel electrode (anode) 903.In such case it will be preferable that the current controlling TFT bean n-channel TFT.

It is also noted that in this embodiment, a shape with an cave (calledthe cave structure hereinafter) consisting essentially of a wiring line909 and a separation portion 910 is provided. The cave structure made ofthe wiring line 909 and the separation portion 910 shown in FIG. 9 ismanufacturable by a method having the steps of laminating a metalconstituting the wiring line 909 and a material (e.g. metal nitrides)that forms the separation portion 910 and has a lower etch rate than themetal and then of etching the same. With use of this shape, it ispossible to prevent the pixel electrode 903 and the wiring line 909 fromelectrically shorting with the cathode 905. Additionally in thisembodiment, unlike standard active matrix type luminescent devices, thecathode 905 on a pixel is formed into a stripe shape (in a similarmanner to that of the cathode of a passive matrix).

Here, an appearance of the active matrix type luminescent device of FIG.9 is shown in FIGS. 10A and 10B. Note here that an upper plan view isshown in FIG. 10A whereas a sectional view taken along line A-A′ of FIG.10A is shown in FIG. 10B. Additionally the reference numerals used inFIG. 9 are also used here.

Numeral 1001 indicated by dotted lines denotes a source side drivecircuit; 1002 denotes a pixel portion; 1003 is a gate side drivecircuit. In addition, 1004 indicates a cover material, and 1005 is aseal material, wherein a space 1007 is provided in interior partsurrounded by the seal material 1005.

Additionally, numeral 1008 denotes a wiring line which transfers signalas input to the source side drive circuit 1001 and gate side drivecircuit 1003, which receives a video signal and a clock signal from aflexible printed circuit (FPC) 1009 for use as an external inputterminal. Note that although the FPC alone is depicted herein, a printedwiring board (PWB) is attachable to this FPC. The luminescent device ofthe subject patent application includes an IC-mounted luminescent moduleas well as a luminescent module with either the FPC or the PWB attachedonto a luminescent panel.

An explanation will next be given of the sectional structure withreference to FIG. 10B. The pixel portion 1002 and the gate side drivecircuit 1003 are formed at upper part of the substrate 901, wherein thepixel portion 1002 is formed of a plurality of pixels each including thecurrent controlling TFT 902 and the pixel electrode 903 electricallyconnected to the drain of the current controlling TFT. Additionally thegate side drive circuit 1003 is formed using a CMOS circuit with acombination of the n-channel TFT 907 and the p-channel TFT 908.

The pixel electrode 903 functions as the anode of a luminescent element.In addition an interlayer insulating film 1006 is formed at the oppositeends of the pixel electrode 903, and the organic compound layer 904 andthe cathode 905 of the luminescent element are formed on the pixelelectrode 903.

The cathode 905 also serves as a common wiring line for a plurality ofpixels and is electrically connected via the connection lead 1008 withthe FPC 1009. Further all the elements involved in the pixel portion1002 and the gate side drive circuit 1003 are covered with theprotective film 906.

Note that the cover material 1004 is adhered by the seal material 1005.Additionally a spacer formed of a resin film may be provided in order toretain a distance between the cover material 1004 and the luminescentelement. And an interior of the seal material 1005 becomes a sealedspace, in which a inactive gas such as nitrogen or argon or else isfilled. Optionally it is also be effective to provide in this sealedspace a moisture absorption material such as barium oxide.

Note that while a glass, a ceramics, a plastic or metals are usable asthe cover material, it must be optical transmissivity in the case ofirradiating light onto the cover material side. Additionallyfiberglass-reinforced plastics (FRP), polyvinylfluoride (PVF), Mylar,polyester or acryl is useable as the plastic material.

The luminescent element 914 formed on the substrate is sealed by usingthe cover material 1004 and the seal material 1005 and thus it ispossible to completely shield it from the outside and prevent invasionof material which accelerates degradation of organic compound layers dueto oxidation such as water and oxygen. Thus it is possible to obtain theluminescent device with high reliability.

Another luminescent device different in structure from the one discussedin FIG. 9 will be explained with reference to FIG. 15. Arrangements of aswitching TFT 1513 and a current controlling TFT 1502 in a pixel portion1511 and arrangements of a p-channel TFT 1508 and an n-channel TFT 1507in a driver circuit 1512 are similar to those in FIG. 9. A method offorming a luminescent element 1514 comprising an anode 1503, an organiccompound layer. 1504, and a cathode 1505 is different from that shown inFIG. 9.

Although in FIG. 9 vacuum evaporation method is used for formation ofthe luminescent element, in this embodiment a structure shown in FIG. 15is formed by employing a method that an ionized organic compound isvacuum evaporated (ion-plating method). Note that this structure isdesirable because of its capability to permit reflection of lightemitted. Additionally the luminescent element 1514 is coated with aprotective film 1506 formed of an insulating film containing silicon.

Note that the luminescent device in this embodiment is capable ofdeposition using the deposition apparatus explained in the embodiments 1to 3.

Embodiment 5

In this embodiment an explanation is given of a luminescent device ofthe passive type (simple matrix type) which is manufactured by thedeposition apparatus of the present invention with reference to FIG. 11.In FIG. 11, numeral 1101 denotes a glass substrate whereas 1102 denotesan anode formed of a transparent conductive film. In this embodiment achemical compound comprising indium oxide and zinc oxide is formed byvacuum evaporation as the transparent conductive film. Note thatalthough not shown in FIG. 11, a plurality of anodes are laid out in adirection parallel to the surface of drawing paper sheet.

In addition, cathode partition walls (1103 a. 1103 b) are formed so thatthese intersect the anodes 1102 laid out into a stripe shape. Thecathode partition walls (1103 a, 1103 b) are formed in a verticaldirection to the surface of the drawing sheet.

Next, an organic compound layer 1104 is formed. The organic compoundlayer 1104 thus formed here preferably has a plurality of functionregions by combination a plurality of organic compounds each of whichhas function of the hole injectability, hole transportability,luminescent ability, blocking ability, electron transportability orelectron injectability.

Note that in this embodiment also, a mixed region is formed betweenadjacent function regions. Additionally the mixed region is formed byusing the method indicated in the embodiments stated supra.

Also note that these organic compound layers 1104 are formed alonggrooves defined by the cathode partition walls (1103 a, 1103 b) and thusare laid out into a stripe shape in the vertical direction to thesurface of the drawing sheet.

Thereafter, a plurality of cathodes 1105 are laid out into a stripeshape in such a manner that these cross the anodes 1102 with thevertical direction to the surface of the drawing sheet becoming thelongitudinal direction thereof. Additionally in this embodiment, thecathodes 1105 are made of MgAg and fabricated by vacuum evaporation. Inaddition, although not specifically depicted herein, the cathodes 1105are designed so that a wiring lines are extended to reach portions towhich an FPC is attached, thereby enabling application of a givenvoltage. Further, after forming the cathodes 1105, a silicon nitridefilm is provided as a protective film 1106.

Through the processes above, a luminescent element 1111 is formed on thesubstrate 1101. Note here that in this embodiment, lower side electrodesare the anodes 1102 with optical transmittance so that light produced atan organic compound layer emits onto a lower surface (substrate 1101side). However, it is also possible that the structure of theluminescent element 1111 is reversed to thereby let the tower sideelectrodes be cathodes with optical shieldability. In such case, lightproduced at the organic compound layer 1104 is emitted to an uppersurface (opposite side to substrate 1101).

Next, prepare a ceramics substrate for use as a cover material 1107.With the structure of this embodiment, though the ceramics substrate isused due to its superiority of light shielding performance, obviously,in case the structure that the luminescent element 1111 is reversed inthe way described previously, a substrate made of plastic or glass maybe used in view of the fact that the cover material 1107 is better inlight transmittance.

The cover material 1107 thus prepared is then adhered by a sealingmaterial 1109 made of ultraviolet ray hardenable resin. Note that aninterior 1108 of the seal material 1109 becomes an air-tight closedspace, which is filled with an inactive gas such as nitrogen or argon.Optionally it will also be effective to provide in this sealed space1108 a moisture absorption material such as barium oxide. Lastly attachan anisotropic conductive film (FPC) 1110, thus completing the passivetype luminescent device.

It should be noted that the luminescent device as indicated in thisembodiment is manufacturable by use of any one of the depositionapparatuses indicated in the embodiments 1 to 3.

Embodiment 6

Being self-luminous, a luminescent device using a luminescent elementhas better visibility in bright places and wider viewing angle thanliquid crystal display devices. Therefore various electric appliancescan be completed by using the luminescent device of the presentinvention.

Given as examples of an electric appliance that employs a luminescentdevice manufactured in accordance with the present invention are videocameras, digital cameras, goggle type displays (head mounted displays),navigation systems, audio reproducing devices (such as car audio andaudio components), notebook computers, game machines, portableinformation terminals (such as mobile computers, cellular phones,portable game machines, and electronic books), and image reproducingdevices equipped with recording media (specifically, devices with adisplay device that can reproduce data in a recording medium such as adigital video disk (DVD) to display an image of the data). Wide viewingangle is important particularly for portable information terminalsbecause their screens are often slanted when they are looked at.Therefore it is preferable for portable information terminals to employthe luminescent device using the luminescent element. Specific examplesof these electric appliance are shown in FIGS. 12A to 12H.

FIG. 12A shows a display device, which is composed of a case 2001, asupport base 2002, a display unit 2003, speaker units 2004, a videoinput terminal 2005, etc. The luminescent device manufactured inaccordance with the present invention can be applied to the display unit2003. Since the luminescent device having the luminescent element isself-luminous, the device does not need back light and can make athinner display unit than liquid crystal display devices. The displaydevice refers to all display devices for displaying information,including, ones for personal computers, for TV broadcasting reception,and for advertisement.

FIG. 12B shows a digital still camera, which is composed of a main body2101, a display unit 2102, an image receiving unit 2103, operation keys2104, an external connection port 2105, a shutter 2106, etc. Theluminescent device manufactured in accordance with the present inventioncan be applied to the display unit 2102.

FIG. 12C shows a notebook personal computer, which is composed of a mainbody 2201, a case 2202, a display unit 2203, a keyboard 2204, anexternal connection port 2205, a pointing mouse 2206, etc. Theluminescent device manufactured in accordance with the present inventioncan be applied to the display unit 2203.

FIG. 12D shows a mobile computer, which is composed of a main body 2301,a display unit 2302, a switch 2303, operation keys 2304, an infraredport 2305, etc. The luminescent device manufactured in accordance withthe present invention can be applied to the display unit 2302.

FIG. 12E shows a portable image reproducing device equipped with arecording medium (a DVD player, to be specific). The device is composedof a main body 2401, a case 2402, a display unit A2403, a display unit B2404, a recording medium (DVD or the like) reading unit 2405, operationkeys 2406, speaker units 2407, etc. The display unit A 2403 mainlydisplays image information whereas the display unit B 2404 mainlydisplays text information. The luminescent device manufactured inaccordance with the present invention can be applied to the displayunits A 2403 and B 2404. The image reproducing device equipped with arecording medium also includes home-video game machines.

FIG. 12F shows a goggle type display (head mounted display), which iscomposed of a main body 2501, display units 2502, and arm units 2503.The luminescent device manufactured in accordance with the presentinvention can be applied to the display units 2502.

FIG. 12G shows a video camera, which is composed of a main body 2601, adisplay unit 2602, a case 2603, an external connection port 2604, aremote control receiving unit 2605, an image receiving unit 2606, abattery 2607, an audio input unit 2608, operation keys 2609, eye pieceportion 2610 etc. The luminescent device manufactured in accordance withthe present invention can be applied to the display unit 2602.

FIG. 12H shows a cellular phone, which is composed of a main body 2701,a case 2702, a display unit 2703, an audio input unit 2704, an audiooutput unit 2705, operation keys 2706, an external connection port 2707,an antenna 2708, etc. The luminescent device manufactured in accordancewith the present invention can be applied to the display unit 2703. Ifthe display unit 2703 displays white letters on black background, thecellular phone consumes less power.

If the luminance of light emitted from organic materials is raised infuture, the luminescent device can be used in front or rear projectorsby enlarging light that contains outputted image information through alens or the like and projecting the light.

These electric appliances now display with increasing frequencyinformation sent through electronic communication lines such as theInternet and CATV (cable television), especially, animation information.Since organic materials have very fast response speed, the luminescentdevice is suitable for animation display.

In the luminescent device, luminescent portions consume power andtherefore it is preferable to display information in a manner thatrequires less luminescent portions. When using the luminescent device indisplay units of portable information terminals, particularly cellularphones and audio reproducing devices that mainly display textinformation, it is preferable to drive the device such that nonluminescent portions form a background and luminescent portions formtext information.

As described above, the application range of the luminescent devicemanufactured by using the deposition device of the present invention isso wide that it is applicable to electric appliances of any field. Theelectric appliances of this embodiment can employ as their display unitsany luminescent device shown in Embodiments 4 or 5, which is formed bythe deposition apparatus shown in Embodiments 1 to 3.

Embodiment 7

In this embodiment, the pixel portion structure of the luminescentdevice formed by a deposition apparatus of the present invention isdescribed.

A part of the top surface view of a pixel portion 1911 is shown in FIG.16A. The plural pixels 1912 a to 1912 c are formed in the pixel portion1911. The top surface view shows the state of an insulating layer 1902formed to cover the edge portion of the pixel electrode formed in apixel. Thus, the insulating layer 1902 is formed to cover a source line1913, a scanning line 1914 and a current supply line 1915. Theinsulating layer 1902 also covers the region a (1903) where connectionportion between the pixel electrode and the TFT is formed at the bottomthereof.

In addition, FIG. 16B shows a cross-section view taken along the dotline A-A of the pixel portion 1911 shown in FIG. 16A and the state offorming organic compound layers 1905 a to 19105 c on the pixel electrode1901. Further, the organic compound layer composed by same material isformed in the vertical direction to the drawing sheet, and the organiccompound layer composed by different material is formed in thehorizontal direction to the drawing sheet.

For example, the organic compound layer (R) 1905 a emitted red light isformed in the pixel (R) 1912 a, the organic compound layer (G) 1905 bemitted green light is formed in the pixel (G) 1912 b and the organiccompound layer (B) 1905 c emitted blue light is formed in the pixel (B)1912 c. The insulating film 1902 becomes a margin when the organiccompound layer is formed. There is no problem if it is on the insulatingfilm 1902 even if the deposition position of the organic compound layershifts somewhat, and the organic compound layer composed by differentmaterial comes in succession on the insulating film 1902 as shown inFIG. 16B.

In addition, FIG. 16C shows a cross-section view taken along the dotline B-B′ of the pixel portion 1911 shown in FIG. 16A and the state offorming the organic compound layer 1905 on the pixel electrode 1901 sameas FIG. 16B.

The pixel taken along the dot line B-B′ have a structure shown in FIG.16C, because the organic compound layer (R) 1905 a emitted red lightsame as the pixel (R) 1912 a is formed in above-mentioned pixel.

Therefore, the organic compound layer (R) 1905 a emitted red light, theorganic compound layer (G) 1905 b emitted green light and the organiccompound layer (B) 1905 c emitted blue light are formed in the pixelportion 1911. Thus, the full-color of the luminescent device can berealized.

As has been described above, fabricating organic compound layers of theluminescent element by use of the deposition apparatus of the presentinvention makes it possible to continuously form the organic compoundlayers each having a plurality of function regions, which in turnenables preclusion of contamination of impurities at the interface ofadjacent ones of such function regions. Furthermore, it is also possibleto form between the function regions a mixed region consistingessentially of the organic compounds that form respective functionregions, thereby enabling relaxation of energy barrier between organiclayers at the function region interface. This in turn makes it possibleto improve the carrier injectability between the organic layers, thusenabling formation of the organic luminescent elements capable ofreducing drive voltages while at the same time offering longer lifetimethereof.

What is claimed is:
 1. A light-emitting device comprising: a transistorcomprising an interlayer insulating film over a substrate, theinterlayer insulating film comprising an opening; a pixel electrodeelectrically connected to the transistor, the pixel electrodeoverlapping with the opening; an organic compound layer over the pixelelectrode, the organic compound layer comprising: a first mixed regioncomprising a first compound comprising a carbazole group and a secondcompound; and a second mixed region comprising the first compound and athird compound comprising iridium, over the first mixed region; and acathode over the organic compound layer, wherein the second mixed regionis provided between two regions, wherein the two regions consist of thefirst compound, and wherein the first compound has a holetransportability.
 2. The light-emitting device according to claim 1,wherein the first compound is 4,4′-dicarbazole-biphenyl.
 3. Thelight-emitting device according to claim 1, wherein the organic compoundlayer emits a light from a region overlapping with the opening.
 4. Adisplay device comprising the light-emitting device according toclaim
 1. 5. The light-emitting device according to claim 1, wherein anedge portion of the organic compound layer is in contact with theinterlayer insulating film in the opening.
 6. A light-emitting devicecomprising: an insulating film over a substrate; a transistor comprisingan interlayer insulating film over the insulating film, the interlayerinsulating film comprising an opening; a pixel electrode electricallyconnected to the transistor, the pixel electrode overlapping with theopening; an organic compound layer over the pixel electrode, the organiccompound layer comprising: a first mixed region comprising a firstcompound comprising a carbazole group and a second compound; and asecond mixed region comprising the first compound and a third compoundcomprising iridium, over the first mixed region; and a cathode over theorganic compound layer, wherein the second mixed region is providedbetween two regions, wherein the two regions consist of the firstcompound, and wherein the first compound has a hole transportability. 7.The light-emitting device according to claim 6, wherein the pixelelectrode is in contact with the insulating film.
 8. The light-emittingdevice according to claim 6, wherein the first compound is4,4′-dicarbazole-biphenyl.
 9. The light-emitting device according toclaim 6, wherein the organic compound layer emits a light from a regionoverlapping with the opening.
 10. A display device comprising thelight-emitting device according to claim
 6. 11. The light-emittingdevice according to claim 6, wherein an edge portion of the organiccompound layer is in contact with the interlayer insulating film in theopening.
 12. A light-emitting device comprising: an insulating film overa substrate; a transistor comprising an interlayer insulating film overthe insulating film, the interlayer insulating film comprising anopening; a pixel electrode electrically connected to the transistor, thepixel electrode overlapping with the opening; an organic compound layerover the pixel electrode, the organic compound layer comprising: a firstmixed region comprising a first compound comprising a carbazole groupand a second compound; and a second mixed region comprising the firstcompound and a third compound comprising iridium, over the first mixedregion; and a cathode over the organic compound layer, a protective filmover the cathode, wherein the second mixed region is provided betweentwo regions, wherein the two regions consist of the first compound, andwherein the first compound has a hole transportability.
 13. Thelight-emitting device according to claim 12, wherein the pixel electrodeis in contact with the insulating film.
 14. The light-emitting deviceaccording to claim 12, wherein the first compound is4,4′-dicarbazole-biphenyl.
 15. The light-emitting device according toclaim 12, wherein the organic compound layer emits a light from a regionoverlapping with the opening.
 16. A display device comprising thelight-emitting device according to claim
 12. 17. The light-emittingdevice according to claim 12, wherein an edge portion of the organiccompound layer is in contact with the interlayer insulating film in theopening.